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I am using a self hosted vs. of Kaltura.
Initially I setup kaltura and also the all-in-one plugin on my WordPress site.
I chose 'I have my own partner ID' and entered it. Everything worked just fine.
I then reinstalled kaltura server and now I need to change my partner ID in the all-in-one plugin, but there is no place for me to 'reset' my partner ID and information.
Short of going into the database and editing the fields manually, there is no way of resetting this.
This should be fixed as it can be a huge issue.


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Our company is in the process of deploying Lync to our users. We intend to use GFI LANGuard to deploy the software to client machines. In testing, the installation has gone smooth on both Vista and Win7 systems. But on XP machines, when the install completes, it closes any open MS Office programs. More troubling, is that Outlook is closed, then reopens automatically, but prompts for a new profile to be created. If you cancel this, then reopen Outlook once more, it's fine, it returns to the user's original profile.
So, the issue is that the majority of our PCs run XP. If we push this out with this behavior, users will freak out, and it will just result in desktop visits, thereby negating the advantage of pushing the installer out via LANGuard.
Google searches have not been too helpful. Any suggestions would be appreciated.

subset: commoncrawl


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I've got a homogenous cluster of several dozen nodes, and I've got CMM modules controlling them.
I need to enable network boot on all these nodes, in order to redeploy them.
Is there a way to do this automatically, without manually logging onto each node via CMM console and changing the boot sequence?


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IREC's 2012 Annual Meeting
The Interstate Renewable Energy Council, Inc.
Monday, September 10, 2012 from 8:30 AM to 4:00 PM (EDT)
Who's Going
San Francisco, California
London, United Kingdom
Florence, Italy
Event Details
What are you doing Monday, September 10, 2012?
Come to IREC's Annual Meeting, September 10, 2012 in Orlando. We'll bring nationally-recognized experts and thought leaders together for updates and discussion, in conjunction with the opening of Solar Power International September 10-13, also in Orlando.
Paula Mints, Director/Energy for Navigant Consulting and widely recognized as an industry expert on PV technologies and markets, will open the meeting. Adam Browning, Executive Director and co-founder of the Vote Solar Initiative, will give the closing remarks.
In between Paula and Adam, here's what else is planned for the day:
- Jane Weissman, Executive Director, IREC, on IREC from 30K feet
- Joe Wiedman, Keyes, Fox & Wiedman, LLP, on regulatory updates
- Amanda Vanega, DSIRE, on policy and incentive trends
- Larry Sherwood, Sherwood Associates, on IREC's U.S. Solar Market Trends Report
- Joe Sarubbi, IREC, on the Solar Instructor Training Network
- Pat Fox, Laure-Jeanne Davignon, IREC, on IREC's Credentialing Program
- Sky Stanfield, Keyes, Fox & Wiedman, LLP, on IREC's Solar Rooftop Permitting Report
- Laurel Varnado, Keyes, Fox & Wiedman, LLP, on the new Freeing the Grid
And as always, we'll recognize our 2012 Innovation and Special Recognition awardees.
Registration is free to IREC members in good standing (as of June 15, 2012), and $75 for non-IREC members.
Not sure of your IREC membership? Contact Jane Pulaski for membership status.
See you in September in Orlando.
Each year, IREC members and other state and industry colleagues generously support IREC's Annual Meeting. And this year, 2012, an especially heartfelt thanks to all our 2012 sponsors, who help us deliver a quality Annual Meeting (and resources) to you. We're enormously appreciative of their confidence in our work.
When & Where
Orlando Hilton
Ballroom Orange B&C
6001 Destination Parkway
Monday, September 10, 2012 from 8:30 AM to 4:00 PM (EDT)
Add to my calendar
The Interstate Renewable Energy Council, Inc.
As national administrator of the Solar Instructor Training Network (SITN), the Interstate Renewable Energy Council, Inc. (IREC) works with a network of nine Regional Training Providers, well-established solar training institutions with expert trainers and first-class training facilities. The SITN is filling a critical need to accessible, high quality, market valued training in solar system design, installation, sales and inspection through train-the-trainer programs. Since 1982, IREC's programs and policies have benefitted energy consumers, policymakers, utilities and the clean energy industry. IRECs work expands consumer access to clean energy; generates information and objective analysis grounded in best practices and standards; and leads programs to build a quality clean energy workforce, including a unique credentialing program for training programs and instructors.


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More Information
Appeals court blocks judge's order to speed drilling permits
Published: Wednesday, March 16, 2011 at 6:01 a.m.
Last Modified: Wednesday, March 16, 2011 at 5:51 a.m.
NEW ORLEANS — A federal appeals court has blocked a judge's order requiring regulators to act on several drilling permit applications.
The federal government filed court documents earlier this month saying it may have to deny the applications if regulators must make a decision within 30 days as ordered.
The order was issued by U.S. District Judge Martin Feldman, who overturned the Obama administration's moratorium on deepwater drilling. That moratorium followed energy company BP PLC's oil spill in the Gulf of Mexico last year.
Feldman ruled last month that the government must act on five applications within 30 days. He later said his ruling also applies to two other permits.
But the 5th U.S. Circuit Court of Appeals issued a stay Tuesday, blocking Feldman's ruling pending the outcome of the government's appeal.
The moratorium that was imposed after the April 20, 2010, rig explosion and resulting oil spill off Louisiana was painful for drilling operators and oil services firms that rely on the industry for business. The ban cost jobs and revenue.
The ban was lifted Oct. 12, but deepwater activities were still stalled for months after that, as regulators required strict new rules to be complied with before they would start issuing permits again for previously suspended activities.
The first deepwater permit since the oil spill for activity that was previously suspended was issued Feb. 28. A second one was issued just recently. Neither of those two permits was among the seven covered by Feldman's ruling, according to a spokeswoman for the Bureau of Ocean Energy Management Regulation and Enforcement.
The blast aboard the Deepwater Horizon rig killed 11 workers. It led to some 200 million gallons of oil spewing from a well a mile beneath the sea, according to government estimates that BP disputes.
Reader comments posted to this article may be published in our print edition. All rights reserved. This copyrighted material may not be re-published without permission. Links are encouraged.


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Darton State College Technology Services Division | Password Information
Home » Technology Services Division
Technology Services Division
Darton State College User Name and Password Look Up
- User Name
- Find your User Name if you do not know it.
- Password (Re)Set
- For: Students ONLY
Set up OR Reset password for:
On Campus Computers, MyDC & GaVIEW
Faculty & Staff
- Password Reset
- For: Faculty & Staff
Reset password for:
On Campus Computers, MyDC & GaVIEW
The Technology Services Division is responsible for the information on this page.
For questions regarding content, or for further information, please contact Email: TSD Helpdesk.
Last Update: June 22, 2016 10:13 AM
The Darton State College web site is maintained by the Technology Services Division.


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Is anyone aware of a plug in, or feature, that would allow someone to create a post from the front end of a blog, which can then be approved in the back end. So, that either guests (or maybe subscribers) could submit posts in the same way as they submit comments?
I want to find someway of adding content to a blog without having to have everyone need to log into the admin pages.


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ATHENS, Greece (AP) " The United States is giving $24 million in new money to help refugees as the European winter approaches.
LONDON (AP) " A British astronaut will attempt to become the first man to run a marathon in space, as part of his 173-day mission to the International Space Station.
MOSCOW (AP) " Lawmakers in Russia-occupied Crimea, which is grappling with a nearly two-week-long blackout, are suggesting parents name their newborn boys Generator to mark the ordeal.
Logan-bound jet over Milton
PARIS (AP) " The latest developments regarding the fight against the Islamic State group in Syria and Iraq: All times local:
LE BOURGET, France (AP) " The latest news from the U.N. climate conference in Paris, which runs through Dec. 11. All times local:
NEW YORK (AP) " In the aftermath of last month's terror attacks in Paris, New York City officials have bolstered security and quietly stepped up outreach efforts to Muslim residents, trying to calm fears of possible hate-filled retaliation while...
JOHANNESBURG (AP) " South African authorities say they are arranging for Oscar Pistorius to appear in court soon following his murder conviction for killing girlfriend Reeva Steenkamp.
MADRID (AP) " Campaigning started Friday for Spain's hotly contested Dec. 20 general election, with the latest opinion poll showing that no party is likely to win a majority and more than 40 percent of voters are still undecided.
NEW DELHI (AP) " The relentless rains that lashed southern India's Tamil Nadu state for three days eased Friday, but the misery of tens of thousands of people was far from over, with large parts of the main city still underwater along with the...
Your daily look at late-breaking news, upcoming events and the stories that will be talked about today:
South Shore Directory
Business Name
Location, ST | website.com


text:
I need to know my page ID. From searching though the forums it seems I get this from going to pages. The weird thing is I do not have any pages. Despite the fact that I have been blogging for a little while and have over 20 posts published.
So I don't know what to do to:
1. I need to create pages without losing content. I'd ideally like the blog posts to be the home page.
2. find an id number.
Thanks in advance for any help.


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Breadcrumb Navigation
Tourism Home > Meeting Planners > Book > Business Services > Member Results
Member Results
1 total result returned.
Sort By:
Xhale Salon & Spa
140 North 4th St. 17th floor of Galt House Suite Tower, Louisville, KY|Downtown|Shopping, Services, Visitor Services, Fitness/Health/Wellness, Fitness/Health/Wellness, Salons/Spas
Xhale Salon- Spa is a full-service salon and spa that caters to men and women. Conveniently located in the heart of downtown Louisville. Our philosophy here at Xhale is to provide exceptional custome...


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Recent Appearances
Media and Entertainment at the Millenium
Mr. Levin spoke about the influence of digital interactivity on the media industry. He focused on how this would…
Third Broadcasting Revolution
Mr. Jordan talked about his company and changes in the broadcasting industry. He gave his overview of the role CBS…


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Elizabeth Warren DESTROYS Donald Trump During ACS Convention
- published: 09 Jun 2016
- views: 202660
Sen. Elizabeth Warren escalated her attacks on presumptive GOP presidential nominee Donald Trump, and tied Mr. Trump's inflammatory comments about a federal judge to what she calls the Republican Party's obstructionism on judicial appointments. In a speech she plans to deliver Thursday night, the Massachusetts Democrat and potential vice presidential pick sharply chastises Mr. Trump for questioning the capabilities of Indiana-born Judge Gonzalo Curiel, who is overseeing lawsuits against Trump University, because of his Mexican heritage. More In Elizabeth Warren"Judge Curiel is one of countless American patriots who has spent decades quietly serving his country," Ms. Warren will say, according to excerpts released ahead of the speech at the American Constitution Society. "Donald Trump is a loud, nasty, thin-skinned fraud who has never risked anything for anyone and serves nobody but himself." A spokeswoman for Mr. Trump didn't immediately respond to a request for comment. Mr. Trump in a statement this week said his remarks had been "misconstrued," but did not apologize for them. Thursday afternoon, MSNBC reported that Ms. Warren would endorse presumptive presidential nominee Hillary Clinton on its Rachel Maddow Show in the evening. In her speech, Ms. Warren also sought to undermine top congressional Republicans' efforts to distance themselves from Mr. Trump's comments on the judge without retracting their endorsement of Mr. Trump as the party's standard-bearer. Both House Speaker Paul Ryan (R., Wis.) and Senate Majority Leader Mitch McConnell (R., Ky. ) have continued to sup...


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Samsung ATIV 915S3G-K01UK
SpecificationsNotebook: Samsung ATIV 915S3G-K01UK (ATIV Book 9 Series)
Processor: AMD A-Series A6-1450
Graphics Adapter: AMD Radeon HD 8250
Display: 13.3 inch, 16:9, 1366x768 pixels, glossy: yes
Weight: 1.6kg
Price: 700 euro
Average of 2 scores (from 3 reviews)
Reviews for the Samsung ATIV 915S3G-K01UK
Source: Gadgetspeak
This is a small and light Windows 8 notebook with touch. If you are looking for a small and light notebook then the Samsung Aviv Book 915s should certainly be on your short list, despite the poor Experience score it was responsive on all tasks and everything I installed ran correctly.
Single Review, online available, Short, Date: 11/25/2013
Rating: Total score: 80% price: 80% performance: 100%
Foreign Reviews
Source: c't - Heft 23/2013
Single Review, , Length Unknown, Date: 10/16/2013
Source: Computer Totaal NL→EN
Single Review, online available, Very Short, Date: 01/18/2014
Rating: Total score: 60%
AMD Radeon HD 8250: Integrated graphics card of the AMD A6-1450 APU ("Temash"). Based on the GCN architecture, integrates 128 shader units and is clocked at 300 - 400 MHz.
Non demanding games should be playable with these graphics cards.
» Further information can be found in our Comparison of Mobile Graphics Cards and the corresponding Benchmark List.
Quad-core APU for ultraportables and tablets. Codenamed "Temash", it is based on the Jaguar architecture and integrates a Radeon HD 8250 graphics card.» Further information can be found in our Comparison of Mobile Processsors.
Above all, this display size is used for subnotebooks, ultrabooks and convertibles. For all three types, this size is quite large. The biggest variety of subnotebooks is represented with this size.
Large display-sizes allow higher resolutions. So, details like letters are bigger. On the other hand, the power consumption is lower with small screen diagonals and the devices are smaller, more lightweight and cheaper.» To find out how fine a display is, see our DPI List.
1.6 kg:
This weight is typical for very big tablets, subnotebooks, ultrabooks and convertibles with a 11-13 inch display-diagonal.
Samsung: The Samsung Group is composed of numerous international businesses, all united under the Samsung brand in South Korea. The meaning of the Korean word Samsung is "tristar" or "three stars". The Samsung brand is one of the most important brands of South Korea. Samsung is an international notebook manufacturer of medium size according market shares and reviews.
70%: This rating is bad. Most notebooks are better rated. This is not a recommendation for purchase.
» Further information can be found in our Notebook Purchase Guide.


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As I rode the elevator to the 20th floor of the Hilton Milwaukee City Center on Wednesday, dual fears competed for dominance in my mind. It was heights vs. embarrassment.
The idea that I would soon be leaning out from a ledge 20 stories above N. 5th St. terrified me, almost as much as the possibility that I would be paralyzed by panic and have to be helped off the roof.
Tom Held leans into the start of his descent on the Hilton City Center. Photo by Mark Hoffman
Some time later, after my hands stopped shaking, I learned that the Special Olympics athletes' oath suited the situation. "Let me win. But if I cannot win, let me be brave in the attempt."
The "Over the Edge" event, a first in Downtown Milwaukee, was organized to raise money for the roughly 85 athletic events put on for 22,000 Special Olympics athletes in Wisconsin each year. Participants (except for the media types) paid $1,500 for the opportunity to rappel down the side of the building, right past the conveniently placed Miller Time Pub.
Over the course of the day, nearly 50 brave men and women inched their way down the brick façade, taking anywhere from 90 seconds to five minutes to reach the pavement.
Dennis Aldridge, the president of Special Olympics Wisconsin, rightly called them "cause-conscious thrill-seekers."
Aldridge made his first rappel in Madison last week, and helped put the endeavor and his own fear in perspective.
"I see our athletes every day overcome challenges far greater than my fear of heights," he said, after reaching solid concrete.
I was reassured somewhat by Aldridge, but more by Matt Staab, who joined me during our short training session on a one-story wall within the Hilton complex. As we waited our turns to test the equipment, I asked Staab why he signed on to rappel down a building. He replied simply, "How can you not?
"It's a fantastic opportunity to do something to overcome your fears," he said, and added that a moderate fear of heights was a healthy fear to have.
It was comforting to see Staab, a picture of calm, next to me on that ledge when we started to follow the instructions to lean back into our harnesses.
I also trusted the Over the Edge crew.
They had assured me that no one had been hurt in their fundraising events around the country over the past six years, and that the safety mechanism on a second rope would catch in the event that I began to drop too quickly. The equipment proved solid and workable during the training session.
All I had to do was squeeze the lever of a simple control mechanism, allow the rope to slowly slide upward, and descend.
And, most importantly, not look down.
Nice and easy now. Photo by Mark Hoffman, Milwaukee Journal Sentinel
On the one or two occasions that I slowed and looked at the surroundings, ripples of panic started to ascend from my stomach. I never felt at-ease enough to fully enjoy the short swings off the building, the blue sky or the sensation of suspension.
It was best to focus on the brick wall in front of me and the steady slide of the rope.
I met Staab again after we returned our helmets and harnesses, and he shared some valuable perspective of the Special Olympians, people he works with as a job coach at the Community Support Network in Madison.
Many of them, for much of their lives, are told what they can't do.
When they compete in Special Olympics, they are given the opportunity to challenge themselves and invariably relish the experience. Those he works with brag about their feats.
"There's a pride in their accomplishment," he said. "They get to do something and see how good it is.
Read and share your thoughts on this story.
For your convenience, the same email address and password can now be used to:


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Launched in October 2005, Feelunique is one of Europe's fastest growing online beauty retailers bringing you outstanding value beauty, grooming and health products straight to your door for free!
Ratings guide
All Feefo reviews are gathered anonymously from genuine customers. Read more about how our review system works.
Nice product. Also used it under eyes and on the eyelids.
My complaint was not resolved at all ripped me off with a voucher
Quick service and great selection of products.
Fast delivery as always.
ok so far,,I continually have very dry lips so need to see how it goes
Tub far too small and difficult to get any balm out.
Good prices, free & fast delivery. Can't beat it!


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Each year at the Color of Wealth Summit we convene hundreds of leading policymakers, business leaders, entrepreneurs, academics, the media and public ...
Read Whole Story
History is often a useful arbitrator of what's possible; for the many who imagine that debt forgiveness simply is not possible, it's worth remembering what happened sixty-one ago: In 1953 in London an agreement was reached to cancel half of Germany's post-WWII debt.
Whether playing or watching sports, the name of the game is the same: who wins?
Every community has many more things to be proud of than a young person's ability to run, jump, throw, and catch. Sport does not build character, it puts character at risk. Sport is just fun.
Mother Nature today, yesterday the loss of a job, the illness of a friend or the unspeakable violence of someone wielding a gun in Arizona forces us to re-decide where to place our faith and what really matters.
Neighbors have the capacity to know what we need. What we need are the gifts that surround us. What we need is each other. And when we act together, we will find the community way. The democratic way.
To those who say our neighborhoods are broken, there is a simple process to help awaken neighborhood power by finding out what people love to do and are willing to teach or learn.
We have lost the imagination of what a neighborhood could do to raise a child. This means there is a great opportunity to organize neighbors to raise the local children -- to become a village that raises the children.
Get top stories and blog posts emailed to me each day. Newsletters may offer personalized content or advertisements. Learn more.


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I have a Postfix mail server running on Ubuntu 8.10 and when
/var/log/mail.log or any other file reaches exactly 2GB of data syslog stops writing any data to the file.
Is there some kind of limit for a file logged through syslog?
I'm discussing with my colleagues if we should be doing an hourly logrotate on the files in question, and hoping that will stop them from hitting this limit. If we have 2-3 hours worth of log files it should be enough when they're this large to find any large problems.


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Sonesta Announces New General Manager at the Royal Sonesta Hotel HoustonMonte Hansen will be joining Sonesta as General Manager of the 485-room Royal Sonesta Hotel Houston as the hotel begins operation today. With over 15 years of experience in hospitality management, Hansen brings new leadership to the hotel team as the hotel transitions to Sonesta management.
Hansen was most recently general manager at the Peabody Hotel in Little Rock, a Four Diamond full service convention center hotel. His experience includes senior management roles for the Greenbrier, the Peabody Hotel Memphis and the Gold Strike Casino Resort.
"Monte is the perfect general manager for this property, as he is familiar with four and five star hotel management and has experience overseeing large multi-purpose convention hotels," said Sonesta President Stephanie Sonnabend. Sonnabend continued, "We envision the Royal Sonesta Hotel Houston to be the market leader, especially for meetings and social functions in the Houston Galleria neighborhood."
The 485-room Royal Sonesta Hotel Houston is AAA approved Four Diamond full service hotel located in the area of the Houston Galleria. The hotel offers 24-hour fitness center, roof top swimming pool, and 50,000 square feet of meeting space. The hotel offers a spectacular location within walking distance of the Houston Galleria. The hotel is a convenient home from which to explore the nearby attractions, professional sporting events, and exciting dining and nightlife the city of Houston and the hotel's uptown neighborhood has to offer.
Discover Royal Sonesta and Sonesta Hotels & Resorts in Atlanta, Austin, Baltimore, Boston, Fort Lauderdale, Hilton Head Island, Houston, Miami, New Orleans, Philadelphia, Sint Maarten (3), Panama, Chile (2), Colombia (5), Ecuador, Peru (6), and Egypt (10). Sonesta ES Suites is an extended stay hotel brand managed by Sonesta in 27 locations found near Boston, Atlanta, Baltimore, Burlington, Charlotte, Chicago, Cincinnati, Cleveland, Colorado Springs, Columbus, Detroit, Flagstaff, Houston, Minneapolis, Oklahoma City, Omaha, Orlando, Parsippany, Princeton, Philadelphia, St. Louis and Tucson. For more about the Sonesta Collection, visit Sonesta.com or call 617.315.9200 or 800.Sonesta (800.766.3782) in the U.S. and Canada.
*High resolution images are available at www.Sonesta.com/media for all Sonesta hotels.
*High resolution images are available at www.Sonesta.com/media for all Sonesta hotels.


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Technique and condition
The work is painted on a sheet of hardboard, manufactured by Royal Board of Sweden. The artist nailed the 3mm thick hardboard onto a framework of four wooden battens which provide some structural support. The front, smooth face was sanded and the corners were protected with thin, short, metal strips that were bent and nailed into the battens. The support is intact but it has a tendency to torque during handling.
The front face of the hardboard and the outer edges of the battens were prepared with a layer of glossy, commercial priming. In an artist's interview 1994, Caulfield responded to an interviewer's question about the priming saying, "...but it was a gloss paint I think I used, it was called eggshell. I used to use different... I can't remember their names, just any commercial brand, Crown, Dulux, etc."
The paint media and some pigments were analysed in 1997. The binding medium was identified as an oil-modified, alkyd resin. The pigments in the light blue background were identified as titanium dioxide with small quantities of china clay and possibly gypsum fillers. The blue pigment was not detected but it is likely to be a pthalocyanine blue, possibly with a small amount of an azo yellow.
Underdrawing is faintly visible to the eye in some areas. When asked about preparation drawings in an artist's interview 1998, Caulfield said, "I might have squared it up or I might have done a tracing, although I can't remember tracing them at the time. I never projected anything. I drew on to the hardboard, just transfer it [the image] visually... fairly freely and make corrections until I got it just right." Under infrared examination the extent of the underdrawing becomes apparent, showing freely sketched lines and some changes in the positions of flowers.
Opaque paints were layered onto the front face in solid lines and fields with no blending of colours on the surface. Generally, a colour field was laid in first, then the black outlines were painted on, then another layer of colour may be applied. From the artist's interview 1998 Caulfield said, "It is likely I would have drawn the vase and then coloured them in... I would have touched it up, I never got them accurate at the first go."
Some edges show a slight amount of wet-in-wet mixing, most likely unintentional. Masking tape was used to achieve the crisp edges of the black, straight lines surrounding the vases and flowers. There is some paint bleed onto the surrounding green-blue paint. The blue-green paint in between the double lines is not as glossy as the surrounding paint and has taken on the slightly roughened texture of the masking tape adhesive surface.
The paint is generally very smooth, flat and glossy. However, there are number of inclusions across the surface. The surface is broken with numerous tiny, sharp bumps, and small nail heads around the outer front edge also break the flat plane of the surface. The paint thickness varies slightly across the surface according to the number of paint layers in a particular field or line.
Paint was applied with a brush. In some areas the application is somewhat uneven. For example, the background was applied largely in broad strokes, vertical and horizontal, first in a yellow-green colour, then covered in a blue-green colour. A small patch of the yellow-green paint remains exposed between the red flower and green stem in the right floral element. The blue-green paint was applied after the flowers and vases were painted. The paint had some flow when it was applied but not enough to settle out the brushstrokes completely. Thus, the area around the flowers and vases is slightly uneven, showing shorter brush strokes following the contours of the shapes, in contrast to the broad, even, strokes of the rest of the background. The contours are not precisely followed, occasionally exposing the yellow-green paint below. The paint has also built up slightly more thickly, resulted in some wrinkling. The painting is not varnished.
Paint is flaking away from the edges and surfaces of the nails, around the perimeter of the front face. There are a series of losses along the front bottom edge which include losses to the paint and ground layers and gouges in the wood. The corners are scuffed with small losses and scratches through the paint. The other edges have small paint and ground losses, some scratches and scrapes. Apart from these damages, the paint is good condition.
Patricia Smithen
September 2001


text:
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Taco Pumps Combine with Munchkin Boilers for a Heating System That Would Make an Old Salt Proud
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Case Studies
Brian Germain, owner of Germain Plumbing & Heating in Attleboro, MA always uses Taco pumps and other equipment for the light commercial and industrial jobs that keep his 16-employee company busy year-round. "Tacos long been king in our area, of course," he says, but more importantly from my standpoint, weve never experienced a problem with any Taco product."
True to his word on using Taco, Germain installed two Taco 1618 and three 1600 pumps along with Taco 007 circulators and Taco Flo-Cheks in what has to be one of the cleanest, most efficient mechanical rooms to be found anywhere in this case inside the Reeves Company, Inc., also of Attleboro. Reeves, a small manufacturer of plastic and metallic name badges for use by government agencies, airlines and car rental agencies, hired Germain Plumbing & Heating last year to retrofit its aging heating system.
In business since 1948, Reeves occupies about 18,000 sq. ft. of office, assembly and warehouse space and employs around 25 people. The one-story building was constructed in three phases over the years, so indoor comfort varied depending on what section of the building the companys employees worked in. By 2005 the original H.B Smith boiler converted over to gas from oil at one point in its operational life and now much less than efficient in its heat output -was at the end of its usefulness. Company president Tom Reeves, son of the companys founder, decided it was time for a new state-of-the-art heating system that he would help design himself.
Brian Germain presented a design that included two Munchkin high efficiency gas-fired boilers model 399-M boasting 92 AFUE. Munchkin boilers are very efficient, have a reputation for excellent reliability, and are quiet running," says Brian. Despite the extra cost, however, Tom Reeves wanted three Munchkin boilers so that the system could cycle all three equally for greater efficiency. Tom is a former U.S. Navy submariner who served in diesel-powered subs, so he likes maximum achievable efficiency, redundancy and cleanliness. He also knows a thing or two about mechanics, piping schemes and heat transfer from his Navy days because, as he relates, Every sailor on board a diesel sub had to know how to fix things because you never knew when you might have to during an emergency."
Germain and Reeves created eight zones for the heating system, and Reeves investigated and then installed a software control system, modeled on Munchkins, that would monitor his heat system, adjust for heat loss within the different zones, and provide us with a constant measure of how were doing in terms of efficiency." Assisted by a Taco outdoor temperature reset, the software system maintains a constant indoor air temperature between 72-74 F. It cycles the three Munchkin boilers for equal service during the work day. In the summer, when the heat system is off, the software cycles the Taco pumps for five minutes each day so that their internal seals wont dry out.
Based on Reeves suggestions for ease of service and cleanliness, Germain raised the three Munchkin boilers above the mechanical room floor. Also, each of the Taco pumps can be unplugged for maintenance, as needed, without affecting the ongoing operation of the heat system. In a mechanical room that is a delight to the eyes as well as a model of efficiency, pipes painted blue show the return line from the heat zones and red pipes the return line from the trio of Munchkin boilers.
This past winter Tom Reeves saw a 35 percent saving on his heating bill due to the new system. True to his background as a submarine veteran who seeks to leave nothing to chance, he keeps a spare Taco 1800 pump by the mechanical room not that hell ever need it.
For more information about this project, contact Brian Germain at (508) 223-3733.
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I can't easily post to my sites, and, when students post comments to some post I've made, they often get taken to a blank screen (using firefox).
I've done the basic troubleshooting that I've found on the web (eg clear cache/cookies, disable all plugins) to no avail.
The following steps illustrates what I do and the problem:
--In superadmin box in the dashboard I click on 'sites'.
--I click on 'edit' for one of my sites such as the groosp1 site. I have these settings shown:
----Domain http:// is: fle.mpls.k12.mn.us
----path is: /wpblogs/groosp1/
----I've got checked: Update siteurl and home as well.
----It has the incorrect siteurl: http://fle.mpls.k12.mn.us/wpblogs
----I scroll a ways down to the 'home' setting and it has the correct address: http://fle.mpls.k12.mn.us/wpblogs/groosp1/
--I update the siteurl to: http://fle.mpls.k12.mn.us/wpblogs/groosp1
--I scroll to the bottom and click 'update options'.
--Next, if I click on 'add post' at the top of this screen it will go to a post creation page BUT not for the correct site but instead has this address: http://fle.mpls.k12.mn.us/wpblogs/wp-admin/post-new.php (note the missing /groosp1 in the address). If I publish this post and view it I find it at the root blog page... http://fle.mpls.k12.mn.us/wpblogs/blog/2010/11/16/test5-post/. However,
--If I click on a link to the /groosp1 site, then click on 'site-admin', then click 'add post', create a post and post and view it, It works just find, creating a post on the groosp1 site.
--next I log out
--log back in
--go to superadmin box, again to to 'sites', click on 'edit' for the groosp1 site.
--and it has re-written the siteurl again back to the root site: http://fle.mpls.k12.mn.us/wpblogs
--and if I try to post a blog it will go to the site root, not the groosp1 site I was at.
I've worked many hours on getting a handle on problem, I'd appreciate any links or ideas to check!


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It seems like setting autocorrectionType either enables or disables both (1) the autofill of words as you type and (2) the red underline as you misspell a word.
In the Settings App, there are separate sliders for "Auto-Correct" and "Check Spelling".
I am wondering if there is any way (possibly via workaround) to keep misspelled words underlined in the UITextView but not autofill programmatically using Objective-C?
Any help is greatly appreciated!


text:
I have been using a modified version of the standard WordPress importer (in the Tools menu) where I need to import a custom post type of my system and the categories. The problem is that after the import the relations between the categories and the posts from my post type are inserted with different IDs (because of the auto increment feature).
Is there any reasonable way to export categories + custom posts and import them preserving the structure?


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If ordered today, we estimate your order will be printed, packed and ready for shipment on Friday, July 29.
Sweet Sentiment - Thank You Card
Item Number: DWF23799LDNTV
Sweet Sentiment - Ecru - Thank You Card
Description and Details
Share your thanks and happiness with this poster-style wedding thank you card. For added style, the frame design is printed in the same ink color you choose for your names. This product features thermography printing, an affordable printing process that results in raised lettering.


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MIT Outing Club Boston Rocks
Retailers' Descriptions
Here's what other sites are saying:
The most comprehensive guide to rock climbing and bouldering in eastern Massachusetts. Second edition.. . . Filled with helpful and accurate beta on more than 800 routes in 50 areas of the state. Includes detailed route maps, directions, GPS coordinates. Paperback; 242 pages; measures 6 x 9 inches.
MIT Outing Club Boston Rocks
previously retailed for:
The MIT Outing Club Boston Rocks is not available from the stores we monitor. It was last seen July 27, 2015 at EMS.
If you're looking for a new us northeast guidebook, check out the best reviewed current models.


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It's a Reading Rainbow!Friday, June 3rd, 2016
Authors, quotes and books………….
Authors, quotes and books………….
A collection of Fairy themed items from my Etsy shop.
Here's a recent collage creation of mine, Alice in Wonderland themed with the "Drink Me" bottle on vintage Bingo card.
Currently available in my Etsy shop.
I love using vintage buttons in my jewelry and collage, especially white mother of pearl, so pretty! Here's a grouping of jewelry and a collage I've made using buttons. Everything shown is currently in my Etsy shop.
I'm adding lots of fun Halloween items to my Etsy shop like these collages done on vintage Bingo cards.
Are you a good witch or a bad witch?
Instead of a black cat these young witches have a black dog.
This time around on the Lawnscaping Challenge blog it's paper piecing. For me it's never too early to start thinking about Halloween so I decided to make a Halloween Shadow box using 3 different Lawn Fawn sets, Hebbie Jebbies, Critters in the 'Burbs and Harvest Season. I can't wait until Halloween so I can put it on my mantle!
I've been holding on to a bunch a sea shells from a trip to Florida years ago and now I know why I saved them! I stamped the mermaid image from "Stampendous" and colored it with Spectrum Noir markers and added glitter to her tail with a clear Starburst gel marker from Sakura. I adhered vintage map pattern paper from CTMH on a 5″ x 7″ canvas board and inked the edges with a sponge and brown stamping ink and then layered the mermaid image on top. Then using a strong clear glue I added the shells around the edges along with a brass star fish charm and also added some real beach sand under her with the same glue. I laid out my shells before I glued them down to make sure they looked nice and would fit. I also added a snippet of text cut from a vintage book that says "Under the Sea". I think she turned out really lovely.
This piece is currently for sale in my Etsy shop.
I just did a review over on Craft Gossip using the Silhouette Fabric Interfacing material which allows you to cut out fabric with a Silhouette die cutting machine. I was amazed at how clean it cut! For my project I cut out some banners, a bird and the word "happy" and ironed them onto some unbleached muslin, sewed on some buttons, added some ribbon knots and put it in a wooden embroidery hoop. I love my blue bird of happiness wall hanging, I think it's adorable!


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Police: Vt father apparently killed son, then selfDecember 20,2013
ESSEX Police in Essex say a man apparently killed his 14-year-old son and then himself.
Police said they found the bodies Wednesday in a second-floor apartment on Carmichael Street. They have been identified as Gunnar Schumacher, a freshman at Essex High School, and his father, 49-year-old Ludwig Sonny Schumacher.
Ludwig Schumacher was a former Vermont National Guard officer and state Republican campaign official.
Police said he was going through a divorce and that a final relief-from-abuse order was granted to a Christina Schumacher in August. Police said they had not received any reports of domestic assault or arrests involving Ludwig Schumacher.
Police Chief Brad LaRose said officers initially responded to the apartment for a report of a mans suicide by hanging.
Autopsies were scheduled.MORE IN This Just InPHILADELPHIA Many delegates from Vermont arrived at the Democratic National Convention this... Full StoryWhite River Junction A Windsor Superior Court judge this week denied a prison sentence... Full StoryBARRE A Maine woman is accused of forging checks and selling off items that didnt belong to her. Full Story
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|Publication number
|Publication type
|Application number
|Publication date
|Nov 22, 1983
|Filing date
|Oct 29, 1980
|Priority date
|Oct 29, 1980
|Also published as
|Publication number
|Douglas C. Neckers
|Original Assignee
|Neckers Douglas C
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (4), Non-Patent Citations (7), Referenced by (27), Classifications (32), Legal Events (1)
|External Links: USPTO, USPTO Assignment, Espacenet
Cl DESCRIPTION
1. Technical Field
The present invention is based upon work supported by the National Science Foundation under NSF Grant DMR78-08493.
The present invention is concerned with new organic compounds which are particularly suitable as photoinitiators. The present invention is especially concerned with peresters. The peresters of the present invention are especially useful as photoinitiators for the polymerization of ethylenically unsaturated materials.
2. Background Art
Photoinitiators are free-radical sources which decompose photochemically and are employed especially as initiators in the polymerization of ethylenically unsaturated materials. In view of the efficient control photoinitiated polymerization offers, such has assumed great importance in recent years in the printing and electronics industries such as in printing inks, paints, and photoresist coatings.
Among typical commercial initiators are three general types: mixtures of aryl ketones, benzoin ethers, or substituted acetophenones. In past years, highly halogenated aryl hydrocarbons were also used for initiators, but their use is now precluded because they are so highly toxic.
Among the more important commercially used photoinitiators for acrylate polymerization is the so-called "Hammond initiator", benzophenone-Michler's ketone.
A major advantage of the Hammond initiator is the rate by which it initiates radical chain reactions; two important disadvantages are the rather large amount of initiator needed to make the rate of polymerization sufficiently rapid for printing applications and the potential toxicity of one of the initiator partners--Michler's ketone (4,4'-bis(N,N-dimethylamino)benzophenone).
To be of real practical significance as a photoinitiator, a compound must be relatively thermally stable but must also be labile when irradiated with wavelengths of UV or visible light. Accordingly, providing new compounds which possess this combination of properties is quite difficult. For instance, various benzophenone derivatives of benzoyl peroxide have been studied. For example, see Leffler et al; Journal American Chemical Society, 1971, 93, 7005 et seq. However, such derivatives are not especially stable thermally. It has also been noted that the photochemical efficiency of triplet benzophenone sensitized decompositions of peroxides in solution is low (e.g.--see Walling et al, Journal American Chemical Society, 1965, 87, 3413 et seq.).
An object of the present invention is to provide new compounds which have the requisite combination of relative thermal stability and efficient photodecomposability to be effective and practical photoinitiators.
The compounds of the present invention are peresters which contain a light absorbing chromophoric moiety. The compounds of the present invention exhibit thermal stability characteristics. However, the compounds of the present invention, unlike prior known peresters, are readily photodecomposable and effective photoinitiators for the polymerization of ethylenically unsaturated compounds. The present invention also makes it possible to control or tune the photodecomposition of the compounds by the absorption characteristics of the light-absorbing chromophore portion of the compound.
The compounds of the present invention are represented by the formula: ##STR3## wherein R is an alkyl group; and ##STR4## is a chromophore group.
The present invention is also concerned with photopolymerizable compositions comprising at least one photopolymerizable ethylenically unsaturated material and at least one of the above-discussed peresters.
Moreover, the present invention is concerned with polymerizing the above-defined photopolymerizable compositions by subjecting such to light, and polymer obtained thereby.
The compounds of the present invention are represented by the formula: ##STR5## wherein R is an alkyl group; and R1 is an organic or hydrocarbyl group such that the ##STR6## group is a chromophore group which produces an excited state by absorption preferably by n-π* absorption and which is free from nonbenzenoid unsaturation and/or polymeric moiety from nonbenzenoid unsaturated monomeric moiety. R is an alkyl group which generally contains 1 to 22 carbon atoms and preferably 1-12 carbon atoms which may be straight or branched chain. The preferred R groups preferably contain a tertiary carbon atom connected to the oxygen atoms for increased thermal stability. The most preferred R group is tert.-butyl.
Examples of some suitable R1 groups are alkyl groups, cycloalkyl groups, aryl groups, substituted aryl groups, aralkyl groups; alkaryl groups; and heterocyclic groups. Generally the R1 groups contain from 1 to 22 carbon atoms, and preferably 1-12 carbon atoms.
Examples of some alkyl groups are methyl, ethyl, t-butyl, t-amyl, hexyl, 2-ethylhexyl, nonyl and octodecyl.
Examples of some suitable aryl groups include phenyl, phenanthryl, and anthracyl.
Examples of some cycloalkyl radicals include cyclopropyl, cyclopentyl, cyclobutyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclododecyl.
Examples of some aralkyl groups are phenylmethyl and naphthylethyl.
Examples of some alkaryl groups include tolyl, xylyl and cumyl.
Examples of substituted aryl groups in addition to alkaryl include alkoxy-substituted aryl groups, such as methoxyphenol. The substituted aryl groups usually contains 1, 2 or 3 substitutions which are usually ortho and/or para with respect to the carbonyl group to which the substituted aryl group is connected.
The heterocyclic groups generally contain 5-6 members in the ring and contain S, O and/or N in the ring and include morpholinyl, piperidyl, thiophenyl, and furanyl.
The preferred R1 groups are aryl and substituted aryl groups and the most preferred R1 groups are phenyl and alkyl and/or alkoxy-substituted phenyl wherein the alkyl and/or alkoxy groups contain 1 to 22 carbon atoms and preferably 1-12 carbon atoms.
The two carbonyl groups located on the benzene rings can be ortho, meta, or, preferably, para to each other.
Some compounds of the present invention include ##STR7## wherein R1 ═R2 ═R3 ═H
The compounds of the present invention can be readily obtained from the corresponding carboxylic acids. In particular, the corresponding carboxylic acid can be reacted at elevated temperature (e.g. up to about 60� C.), preferably at reflux, with, for example, thionyl chloride to form the corresponding acid chloride. Next, the acid chloride can be reacted with a hydroperoxide, such as tert.-butyl hydroperoxide in the case of R being t-butyl, usually in the presence of a tertiary amine, preferably triethylamine. In addition, it is preferred that this stage of the preparation be carried out in the presence of a diluent, such as ether, benzene, or dichloromethane.
The compounds of the present invention are especially useful as photoinitiators in the polymerization of photopolymerizable ethylenically unsaturated materials. The photopolymerizable materials can be monomeric or prepolymers containing one or more ethylenically unsaturated groups.
Examples of some suitable photopolymerizable materials include esters of unsaturated monocarboxylic acids or dicarboxylic acids, e.g. esters of acrylic acid, methacrylic acid, α-cyanacrylic acid, sorbic acid, fumaric acid or itaconic acid with aliphatic, cycloaliphatic or aromaticaliphatic monohydric to tetrahydric alcohols of 3 to 20 carbon atoms, e.g. methyl acrylate and methacrylate; n-, i- and t-butyl acrylate and methacrylate; 2-ethylhexyl acrylate; lauryl acrylate; dihydrodicyclopentadienyl acrylate and methacrylate; methylglycol acrylate; hydroxyethyl acrylate and methacrylate; hydroxypropyl acrylate and methacrylate; ethylene glycol diacrylate; diethylene glycol diacrylate; triethylene glycol diacrylate; neopentylglycol diacrylate and dimethacrylate; 1,4-dimethylolcyclohexane diacrylate; pentaerythritol-triacrylate, -tetraacrylate, -trimethacrylate and -tetramethacrylate; ethyl α-cyanacrylate; ethyl crotonate, ethyl sorbate; diethyl fumarate; and the diacrylate and dimethacrylate or oxyalkylated bisphenol A; amides of acrylic acid or methacrylic acid which may or may not be substituted at the nitrogen by alkyl, alkoxyalkyl or hydroxyalkyl, e.g., N,N'-di-methylacrylamide, N-isobutylacrylamide, diacetoneacrylamide; N-methylolacrylamide, N-methoxymethylacrylamide, N-butoxymethylacrylamide, N-butoxymethylmethacrylamide and ethylene glycol bis(N-methylolacrylamide)ether; vinyl esters of monocarboxylic acids or dicarboxylic acids of 2 to 20 carbon atoms, e.g., vinyl acetate, vinyl propionate, vinyl 2-ethylhexanoate, vinyl versatate and divinyl adipate; vinyl ethers of monohydric or dihydric alcohols of 3 to 20 carbon atoms, e.g., isobutyl vinyl ether, hexyl vinyl ether, octadecyl vinyl ether, ethylene glycol divinyl ether, diethylene glycol divinyl ether, butanediol divinyl ether and hexanediol divinyl ether; mono-N-vinyl compounds, e.g., N-vinylpyrrolidone, N-vinylpiperidone, N-vinylcaprolactam, N-vinylmorpholine, N-vinyloxazolidone, N-vinylsuccinimide, N-methyl-N-vinylformamide and N-vinylcarbazole; allyl ethers and allyl esters, e.g., trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol triallyl ether, diallyl maleate, diallyl fumarate or diallyl phthalate; vinyl and vinylidine halides, e.g., vinyl chloride and vinylidene chloride; and vinyl aromatics, e.g., styrene, alkyl styrenes, halostyrenes and divinylbenzenes.
Examples of some polymeric photopolymerizable materials include unsaturated polyesters obtained, for instance, from α,β-unsaturated dicarboxylic acids, e.g., maleic acid, fumaric acid or itaconic acid, and aliphatic, cycloaliphatic or non-phenolic aromatic diols, e.g., ethylene glycol, diethylene glycol, triethylene glycol, propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, but-2-ene, 1,4-diol, neopentylglycol, hexane-1,6-diol or oxyalkylated bisphenol A; unsaturated epoxide-acrylates obtained, for instance, from monofunctional epoxides and acrylic acid or methacrylic acid, by the method of U.S. Pat. No. 2,484,487, bifunctional epoxides and unsaturated fatty acids, by the method of U.S. Pat. No. 2,456,408, polyfunctional aromatic epoxides and crotonic acid, by the method of U.S. Pat. No. 2,575,440 or polyfunctional aromatic or aliphatic fatty glycidyl ethers and acrylic acid or methacrylic acid, by the method of U.S. Pat. No. 2,842,851; unsaturated polyurethanes (urethane-acrylates) prepared from hydroxyalkyl acrylates and diisocyanates, with or without polyols or polyamines; unsaturated copolymers, prepared, for example, by reacting copolymers, containing maleic anhydride groups, with unsaturated alcohols; or acrylic ester copolymers containing carboxylic acid groups or polyesters containing carboxylic acid groups with unsaturated epoxides, e.g., glycidyl acrylates; butadiene polymers in which the double bonds are predominantly present as vinyl side chains; diallyl phthalate prepolymers; and poly-N-vinylurethanes, e.g. prepared, for instance, by reacting vinyl isocyanate with saturated or unsaturated polyesterpolyols, polyether-polyols or polyfunctional alcohols.
The peresters when employed as photoinitiators are usually present in amounts of about 1 to about 10%, and more usually about 1 to about 3% by weight based upon the weight of the photopolymerizable material present. The polymerization of such compositions can be carried out by subjecting or exposing the compositions to light (e.g., UV or visible) of appropriate wavelength absorbable by the chromophore moiety of the perester employed. The compounds of the present invention can be tailored by the particular chromophore group present to provide light absorption properties for a given wavelength selected from a broad spectrum of wavelengths, preferably in the visible and UV ranges. It is preferred that the chromophore group be selected so that it absorbs light in the range of about 250-700 nm. The particular wavelength to employ is determinable by those skilled in the art without undue experimentation once they are aware of the present invention and the particular chromophore group present.
Polymers obtained from polymerization in the presence of the peresters of the present invention have been found to contain as end group the chromophore group from the perester employed; and, therefore, can subsequently be subjected to irradiation to achieve some crosslinking. For instance, polystyrene obtained from irradiating styrene in the presence of t-butyl-4-benzoylperbenzoate contains one benzophenone end group, and is, therefore, crosslinkable at 366 nm.
Polymerization of the composition usually requires exposure to the light for about 30 seconds to about 10 minutes depending upon the amount of initiator present. The time and amount are inversely related. The crosslinking reaction is usually about 102 to 103 times slower than the polymerization and usually requires about 1 to about 20 hours depending upon the amount of initiator employed.
The following non-limiting examples are presented to further illustrate the present invention:
About 1 part of ρ-benzoylbenzoic acid is admixed with about 5 parts of thionyl chloride and a few drops of pyridine, and the mixture is heated to boiling (about 78� C.) and maintained under reflux conditions until the production of HCl ceases. The resulting acid chloride is purified by crystallization from cyclohexane.
About 10 mmol of the acid chloride are dissolved in about 50 mL of ether. The solution is stirred magnetically and cooled in an ice-water bath while a solution of about 11 mmol of tert-butyl hydroperoxide and about 12 mmol of triethylamine in about 20 mL of ether is added over a period of about 5 minutes. After the addition is completed, the reaction mixture is stirred for another hour at ice-water bath temperatures. The desired perester, t-butyl-4-benzoylperbenzoate is obtained by filtration and evaporation. In addition, the perester is purified by chromatography over silica gel having a mesh of about 60 to about 200 using CH2 Cl2 as eluent and then recrystallization from an ether-pentane mixture.
Melting points of the peresters are determined on a Thomas-Hoover capillary melting point apparatus and are uncorrected. Infrared spectra are recorded in KBr disks or neat, using a Perkin-Elmer 337 infrared spectrophotometer (when other conditions are used they are given at the appropriate place). NMR spectra are recorded either on a Varian A-60 or CFT-20 spectrometer with deuteriochloroform as the solvent and tetramethylsilane as the internal reference.
UV spectra are determined using a Beckman Acta MIV spectrophotometer. Mass spectra are obtained using a Varian MAT Model CH-7 mass spectrometer. GLC measurements are made on a Hewlett Packard 5710 A TD or 5710 FID chromatograph. High-pressure LC chromatograms are run on a Waters Associates instrument with UV detection and a Porasil column.
Tert-butyl-4-(4'-methylbenzoyl)perbenzoate is prepared by the above-discussed procedure for the preparation of t-butyl-4-benzoylperbenzoate, except that the starting acid employed is 4-(4'-methylbenzoyl) benzoic acid which is prepared by the Friedel-Crafts reaction of 4-(carbomethoxy)benzoyl chloride with toluene followed by saponification and acidification as suggested in Smith, Journal of American Chemical Society, 1921, 43, 1920, and Firestone et al, Journal Organic Chemistry, 1974, 39, 3384.
Tert-butyl-4-(2',4',6'-trimethylbenzoyl)perbenzoate is prepared by a method similar to that for the preparation of tert-butyl-4-benzoylperbenzoate except that the starting acid employed is 4-(2',4',6'-trimethylbenzoyl) benzoic acid which is obtained by the Friedel-Crafts reaction of 4-(carbomethoxy)benzoyl chloride with mesitylene followed by saponification and acidification as suggested by Benjamins et al, Journal of Chemistry, 1974, 52, 597, and Firestone et al, Journal of Organic Chemistry, supra.
Tert-butyl-4-(4'-methoxybenzoyl)perbenzoate is prepared by the above discussed procedure for the preparation of t-butyl-4-benzoylperbenzoate, except that the acid employed is 4-(4'-methoxybenzoyl)-benzoic acid, and during the preparation, the corresponding acid chloride is dissolved in a mixture of ether and dichloromethane.
Tert-butyl-ρ-butyrylperbenzoate is prepared by the above-discussed procedure for the preparation of t-butyl-4-benzoylperbenzoate, except that the acid employed is ρ-butyryl benzoic acid and is purified by chromatography over neutral aluminum oxide with dichloromethane-ether (5:1) as eluent. The perester obtained is a yellow oil which solidifies after several months in the refrigerator.
About 22 mmol of ο-benzoylbenzoic acid is admixed with about 10 mL of thionyl chloride and heated to reflux for about 4 hours. The thionyl chloride is evaporated and the product obtained is a pseudoacid chloride which is an oil. The oil obtained is then dissolved in about 100 mL of ether and the solution cooled in an ice-salt bath. Over a period of about 15 minutes, a solution of about 23 mmol of t-butyl hydroperoxide and about 24 mmol of triethylamine in 25 mL of ether are added. A yellow color develops upon the addition of the first drops. Stirring is continued for about another hour after the addition is completed. Filtration and evaporation of the reaction mixture gives a yellow oil. The oil is subjected to chromographic treatment over silica gel using CH2 Cl2 as eluent. About 4.5 grams of an oil is obtained which gives a solid on trituration with ether. The solid appears to be the below-defined psueodoperester which, in turn, is crystallized from dichloromethane-ether, giving a colorless compound having an mp of about 126� to about 128� C.; a IR.sub.ν.sbsb.c═o 1790 cm-1 (no C═O of benzoyl group); NMR 1.23 (s, 9H, CH3), 7.2-8.7 (m, 9H, aromatic protons).
The oil is again subjected to chromatography and freed from psuedoperester by dissolving it in ether-pentane mixtures, cooling and then filtering.
The following Table I gives the various physical properties of the peresters in Examples 1a to 1f.
TABLE I__________________________________________________________________________Physical Properties of the Peresters ##STR10## IR absorption, cm-1, in CCl4 νC═O νC═O triplet energyperester yield, % mp, �C. (ketone) (adjacent to perester) UV n - π*, ET,__________________________________________________________________________ kcal/molIa 75 62-64 1665 1770 347 67.7Ib 70 75-77 1665 1770 349 67.4Ic 63 93-95 1665 1770 325Id 78 80-81 1665 1770 pseudoperester mixture oil 1680 1175(neat) 327If perester 126-128 1790(KBr) none > 300Ie Ie 52 oil 1700 1775(neat) tail > 300__________________________________________________________________________
The peresters are dissolved in concentrations as given in Table II. The amount of perester used is in the range of 300-500 mg. The solutions are placed in Pyrex tubes, flushed with nitrogen for 10 min., and sealed with a rubber cap.
After the irradiation, the yield of CO2 is measured by applying N2 pressure and trapping the CO2 with a Ba(OH)2 solution. The photolyzed solutions are evaporated (in the case of perester Ia treatment with excess diazomethane gives the best separation procedure) and again evaporated. Chromatography over 2 mm silica gel plates (E. Merck) with dichloromethane as the developing solvent separates the products. Extraction of the silica gel is done with ether. The identity of each sample is confirmed by GLC or high-pressure LC by comparison with authentic samples or by melting points of the solids.
All the peresters photodecompose with nearly unit quantum efficiency in both polar and nonpolar solvents when irradiated at the wavelength of carbonyl group absorption. In general, the photodecompositions occur as shown in Scheme I below.
The main products from the benzophenone moiety are the parent aryl ketone and the appropriate benzoic acid, though secondary photoproducts such as pinacols and other solvent-derived products are also formed, the quantity depending on the nature of the solvent. The main products and reaction conditions of the photolysis experiments for some peresters of Example 1 are given in Table II.
The decomposition of most of the peresters is faster in methanol than in cyclohexane. In the case of the mesitoyl perester, Ib, the effect of methanol is to slow the rate of decomposition.
The decarboxylation step of each perester derived carboxyl radical is not affected much by the solvent, but pinacol products are more prominent in methanol.
The irradiation of the butyrophenone perester, Ie, shows no evidence for a competing Norrish type II reaction. Thus, there is no acetophenone, no ρ-acetylbenzoic acid, and no ρ-acetyl tert-butylperbenzoate observed among the products from Ie. On the other hand, the formation of about 25% of the methyl ester of the expected acid as a photoproduct is somewhat difficult to explain but may come from a solvent-induced decomposition.
Concerning the byproducts formed, irradiation Ia in cyclohexane gives bicyclohexyl as a secondary photolysis product. This is shown by comparison with an authentic sample and combination of spectroscopic techniques. GLC indicates that minor fractions of C6 H5 --CO--ρ--C6 H4 COO--c--C6 H11 are present in cyclohexane while in CH3 OH a secondary photoproduct is C6 H5 CHOH--ρ--C6 H4 COOH. The same product is formed when 4-benzoylbenzoic acid is irradiated for 2 hours in CH3 OH in 26% yield. The structure of this secondary photoproduct is shown by independent synthesis (reduction of methyl 4-benzoylbenzoate by NaBH4). Among other secondary photoproducts found in small amounts is a mixture of pinacols. These are confirmed by synthesis of a similar pinacol mixture upon irradiation of methyl 4-benzoylbenzoate in isopropyl alcohol.
After photolysis of tert-butyl-4-(2',4',6'-trimethylbenzoyl)perbenzoate (1c) (300 mg in 20 mL of CH3 OH) for 1 hour, the following products are found: 14.1% of CO2, 15.6% of phenyl mesityl ketone, 56.6% of starting perester, and 21.8% of the corresponding acid.
The phenyl mesityl ketone shows no deuterium incorporation (mass spectrometry). The perester shows no deuterium incorporation (NMR).
The recovered perester is irradiated again in cyclohexane solution (25 mL) for 4 hours. The following products are found: carbon dioxide, 44%; bicyclohexyl (21 mg); mesityl phenyl ketone (52%); and the corresponding acid, 46%. No deuterium incorporation in the mesityl phenyl ketone is found.
After photolysis of tert-butyl-ρ-butyrylperbenzoate (1e) (1 mmol in 30 mL of CH3 OH) for about 85 minutes, the following products are found: carbon dioxide, 11%; butyrophenone, 10% (confirmed by high-pressure LC): methyl ρ-butyrylbenzoate (25%) (mp 83�-85� C. from hexane) confirmed by independent synthesis); and ρ-butyrylbenzoic acid (52%) (confirmed by preparation of the methyl ester). No products of a Norrish type II reaction are found.
Kinetic studies are carried out in degassed, sealed tubes by irradiating them with 366 nm light obtained from a Hanovia medium-pressure mercury lamp by combining the Corning Filters 0-52 and 7-60. The decompositions of the peresters are followed by the carbonyl IR absorption adjacent to the peroxide group (O═COO--) (1770 cm-1). Benzophenone-benzhydrol redox actinometry are used throughout the study. In particular, a solution of perester (2 mL) in the appropriate solvent is placed in Pyrex tubes (12-mm diameter), degassed, and sealed under vacuum. Three cycles of freeze-thaw removes dissolved oxygen. The tubes are placed in a merry-go-round around a water-cooled light source, removed at different predetermined intervals, and kept frozen in liquid nitrogen in the dark until analysis is done. The estimation of perester is done by quantitative IR, monitoring the carbonyl peak at 1770 cm-1. None of the products of decomposition or the solvent interfere at this wavelength. Absorbance is measured with a 0.1 mm NaCl cell against solvent reference. With every run, two tubes containing actinometric solutions (benzophenone (0.1 M) and benzhydrol (0.05 M) in benzene are irradiated. The light intensity and quantum yield of benzophenone loss are measured by measuring the decrease in benzophenone content spectrophotometrically (using the benzophenone peak at 345 nm).
Quantum yields of decomposition of the peresters are shown in Table III below and are observed to be near unity in contrast to the low quantum yields of benzophenone-sensitized decomposition of Bz2 O2 as discussed in Walling et al, American Chemical Society, 1965, 87, 3413.
The decomposition rates of the peresters show first-order reaction kinetics with little or no induced decomposition in benzene solution in the concentration range 0.04 to 0.07 M. The apparent first-order photodecomposition rate constants (kd) (up to 40% conversion) in C6 H6 are shown in Table IV below.
In methanol the quantum yield is much higher than in cyclohexane and higher than unity, suggesting the possibility of a solvent-induced decomposition.
To test this possibility, a radical scavenger 2,6-di-tert-butyl-ρ-cresol (TBP) is included in the reaction mixture; under these conditions the quantum yield in CH3 OH reduces in value to that found in benzene. The rate of decomposition in benzene does not alter with addition of TBP, and the quantum yields, both in the presence and the absence of TBP, in methanol and CCl4 are shown in Table V below. Thus, under conditions where the solvent-induced decomposition is eliminated by the radical scavenger, the quantum yield is the same in methanol as in nonpolar solvents.
All the peresters give linear Stern-Volmer plots when naphthalene is used as triplet quencher. The values of the slopes (kq τ) (Table VI below) suggest that the triplet lifetimes of the peresters are short when compared to those of benzophenone alone.
To test the thermal stability of the perester, attempts are made to measure decomposition rates at 80� C. in benzene. While Bz2 O2 shows a decomposition rate comparable to the literature value, the peresters do not decompose at all at 80� C. The thermal rates of decomposition in the dark are measured at 110� C. in chlorobenzene (Table VII below) and are comparable in value to the rates of decomposition of substituted tert-butyl perbenzoates.
TABLE II__________________________________________________________________________The Products of Photolysis from Different Peresterse products, mol % concn, period of unreacted benzoyl-perestersolvent M � 102 irradiation, h perester benzoic acid benzophenone__________________________________________________________________________Ia cyclohexane 2.4 6 0 55 .sup. 36amethanol 2.4 1 0 60 .sup. 29bIb cyclohexane 2.0 2.5 29 27 20 2.2 4 0 46 43methanol 4.2 1 61 13 19CH3 OHd 4.4 1 57 21 16Ie methanol 3.3 1.5 0 .sup. 52c .sup. 10c__________________________________________________________________________ a Minor byproducts are bicyclohexyl and C6 H5 CO--pC6 H4 COO--c-C6 H11. b Further irradiation gives pinacols and C6 H5 CHOH--pC6 H4 COOH. c In addition to the acid, 25% methyl ester of the acid is also found. d Decomposition of Ib in CH2 OH produces no deuterated mesitoyl phenyl ketone nor is there any deuterium in the recovered Ib. e Irradiation light source 300 nm; Pyrex reactors purge with nitrogen.
TABLE III______________________________________Quantum Yields of Perester Decompositionand Sensitized Decomposition of Benzoyl Peroxide benzo- phenone concn, concn, φ ofperester M � 102 solvent M � 102 dec______________________________________Ia 5.90 C6 H6 0.94Ib 6.06 C6 H6 0.80Ic 5.03 C6 H6 0.75Bz2 O2 4.67 C6 H6 5.89 0.32Bz2 O2 3.50 CCl4 3.75 0.17______________________________________
TABLE IV______________________________________Decomposition Rates of the Perestersand Sensitized Benzoyl Peroxidea benzo- initial phenone concn, concn,perester M � 102 M � 102 kd � 104______________________________________ s-1Ia 5.9 1.84Ib 6.06 1.34Ic 5.03 1.45Bz2 O2 4.67 5.89 0.64______________________________________ a Light intensity, I = 6.56 � 1017 quanta/min; solvent, C6 H6 ; temperature 25� C.
TABLE V______________________________________Quantum Yields of the Peresters inMethanol and CCl4 a TBPper- concn, concn,ester M � 102 M � 102 solvent φ of dec______________________________________Ia 7.16 CCl4 1.05 4.78 5.01 CCl4 0.79 3.56 CCl4 0.90 3.56 3.76 CCl4 0.74 5.38 methanol 2.77 5.38 5.08 methanol 0.64Ib 6.15 methanol 1.30 6.15 5.08 methanol 0.62Ic 5.10 methanol 1.54______________________________________ a Radical-induced decomposition of Ia is greater than that of Ic and Ib.
TABLE VI______________________________________Quenching Constants for the Perestersperesters quencher solvent kq τ______________________________________Ia naphthalene CCl4 7.5Ib naphthalene C6 H6 15Ic naphthalene CCl4 15______________________________________
TABLE VII______________________________________Thermal Decomposition of the Peresters initial 1st order concn, dec rate half-life,perester M � 102 M � 105 s-1 t1/2, h______________________________________Ia 5.01 2.88 6.7Ib 5.15 1.80 10.7Ic 5.19 3.03 6.4______________________________________
The peresters all provide efficient photochemical sources of free radicals. Important from a practical view is that their photodecomposition is controllable (effectively it can be tuned) by the absorption characteristics of the absorbing chromophore. Thus ρ-benzoyl tert-butylperbenzoate decomposes smoothly at room temperature with 366 nm radiation. At this wavelength benzoyl peroxide is photostable. In hydrocarbon solvents where the likelihood of solvent-induced decomposition is minimized, the decomposition quantum yield approaches unity (Table III). The quantum efficiency of photodecomposition of the aroyl tert-butylperbenzoates is at least three times that of the benzophenone-sensitized decomposition of benzoyl peroxide, clearly indicating the efficacy of the intramolecular process in contrast to bimolecular energy transfer. In fact, all of the peresters tested decompose with higher quantum yields (by at least a factor of 3) than does benzoyl peroxide in the presence of benzophenone (Table III). The decomposition rates are also 2-3 times higher compared to benzophenone-sensitized benzoyl peroxide decomposition (Table IV). In methanol all of the perester decomposition quantum yields are enhanced, the result of induced decompositions which are chain reactions (Table V).
The potential for an intramolecular reaction in the mesitoyl perester (Ib) is suggested by its apparently slower rate of decomposition in methanol than either that of Ia or Ic under identical conditions. This suggests an intramolecular hydrogen abstraction leading to a photoenol, the latter being stabilized by the alcohol solvent. ο-Alkylbenzophenones give photoenols when the n-π* triplet state abstracts hydrogen from the ortho substituent (see Tammes, Tetrahedron 1976, 32, 405). Though this process is reported to be inefficient for mesitoyl aryl ketones by Matsuura et al, Tetrahedron, 1969, 25, 4487, because the excited state is disrupted from planarity by the excessive ο-methyls, there is reason to believe the latter theory is based on incomplete experimental evidence as discussed by Neckers, PhD Thesis, University of Kansas, 1963.
Photoenolization in the mesitoyl perester (Ib) would be indicated by deuterium incorporation if the reverse reaction is slow compared with intermolecular exchange (Scheme II). Only if the exchange with solvent is slow compared to reversion (a reaction expected to have a rate constant comparable to that of the reverse Norrish type II reaction in t-BuOH) would no deuterium incorporation be observed in the starting material recovered or in the products.
The experiments (Table II) indicate that no deuterium incorporation is observed either in the starting perester Ib or the products. This result suggests that photochemical perester decomposition from Ib is faster than is the intramolecular hydrogen abstraction from the methyl groups.
The result with the butyrophenone perester Ia is similar in that it too indicates that photolytic perester decomposition proceeds much more rapidly than formation of acetophenone derivatives which would be expected from a competitive Norrish type II reaction. The latter reaction is one in which abstraction from the alkyl chain would have to occur more rapidly than perester bond homolysis. This process would be indicated by acetyl products--either in the form of acetophenone, ρ-acetylbenzoic acid, or even perhaps ρ-acetyl tert-butylperbenzoate (Scheme III). None of these are observed.
The point is that few of the typical photochemical reactions of aryl ketones seem to compete with light absorption and perester decomposition--in that order in the case of the UV active peresters. None of the typical n-π* triplet ketone reactions of the aryl ketone systems tested are viable in competition with the homolysis of the --O--O-- bond of the perester unit. ##STR11##
0.2 parts by weight of the photoinitiators of the present invention are incorporated in 10 parts Crystik-PKE 305 (Unsaturated polyester resin from Messr. Maeder, Switzerland). This mixture is stirred until a solution is obtained, which is then drawn out on glass plates with a film drawer (100μ). These films are irradiated with a medium-pressure Hg burner (Hanovia-Gerat, Model 45080). The samples are passed, on a conveyer belt, under the UV-lamp at a rate of 17 m/min. (20 volts).
The following Table gives the number of passes (P) which are necessary in order to obtain, with the photoinitiators according to the invention, films resistant to wiping. In addition, the hardness of the film is determined using a pendulum apparatus according to Konig.
__________________________________________________________________________ Pendulum hardness accord- Passes necessary ing to Konig, H, as a to achieve resistance function of the numberPhotoinitiator to wiping of passes P, H (P)__________________________________________________________________________ ##STR12## 14 23 (14) 26 (16) ##STR13## 14 22 (14) 26 (16) ##STR14## 13 23 (13) 51 (15) ##STR15## 12 24 (12) 38 (14)Benzophenone >20 wet(Comparison example)__________________________________________________________________________
The rate of polymerization is much higher with the peresters than with benzophenone.
Commercial methyl methacrylate monomer is washed three times with 2% NaOH solution to remove stabilizer. It is then washed with distilled water three times, dried with molecular sieves, and distilled under vacuum before use. Polymerization solutions are prepared in cylindrical tubes which are degassed and sealed. The amount of polymer formed is determined by precipitating the polymer with an excess of methanol, washing with methanol, and filtering through fine sintered crucibles (previously weighed) followed by drying in a vacuum oven. The irradiation condition is the same as that in the decomposition rate example hereinabove.
The results are shown in Table VIII below. The peresters of the present invention are each more efficicnt than is benzophenone-sensitized initiation using benzoyl peroxide or when benzophenone alone is used as an initiator. They are also comparable to the Hammond initiator in rate and have several advantages--by design. The thermal decompositions of the synthesized peresters are slow. In a thermal reaction, these peresters are quite similar to tert-butylperbenzoates.
Under the photolytic conditions employed, methyl methacrylate does not polymerize photochemically in the absence of any initiator.
TABLE VIII______________________________________Rate of Polymerization (Rp) of MMAa benzophenone Rp � 105initiator concn, M � 102 mL-1 s-1______________________________________Ia 8.33Ib 8.31Ic 8.16Bz2 O2 5.5 2.58______________________________________ a Initiator = 5 � 10-2 M, [MMA] = 3.1 M; temperature = 25� C., benzene.
Commercial styrene is washed three times with ice cold 2% NaOH solution followed by washing (four times) with distilled water. The styrene is dried over anhydrous CaCl2 and distilled under vacuum before use. The middle fraction of the distillate is used for polymerization. Solvents are purified by conventional means and distilled under N2 atmosphere.
The irradiations are carried out in degassed (three cycles of freeze-thaw under high vacuum) sealed 15-mm Pyrex tubes. The tubes are placed in a merry-go-round with a filtered UV source of 366 nm at the center and the yield of polymer is measured (below 10% conversion) gravimetrically. In all of the cases, tubes of the same size and same volume of solution are used. Number-average molecular weights of the purified polymers are determined by viscometry in a benzene solution. After the polymerization, an aliquot of 0.5 ml from each reaction tube is placed in 2-ml volumetric flasks. The solvent and excess monomer are evaporated under high vacuum for several hours. The remaining flask contents are dissolved in 0.5 ml of benzene or chloroform and the polymer is precipitated by adding 0.5 ml of n-hexane. The solution then is centrifuged and the IR of the centrifugate is measured to determine undecomposed perester. All of the above procedures are carried out as far as possible in the dark. The light intensity is measured by benzophenone-benzhydrol actinometry and observed to be Io =6.56�1017 quanta/min on the average. The temperature of the tubes is maintained at 30� C.
The decomposition of the initiator employed is followed by IR at 1770 cm-1 (caused by the carbonyl adjacent to the peroxy group) against an appropriate solvent blank. The initiators employed are ρ-benzoylperoxybenzoic acid tert-butylester (Ia) and prior art benzophenone peroxide. In addition, the above procedure is repeated except that methyl methacrylate is employed in place of styrene. Table IX below illustrates the relative quantum yield for the decomposition of the initiators in the recited amounts of monomers, assuming that the quantum yield for the decomposition of the perester and peroxide in the absence of any monomer is one.
TABLE IX______________________________________Relative Quantum Yield (φrel) of Decomposition of Perester orPeroxide in Presence of Styrene and Methyl MethacrylateaPerester PeroxideMonomer MonomerConcentration Concentration[M] [M](M) φrel (M) φrel______________________________________Styrene-benzene Styrene-chloroform8.73 very low 4.26 0.084.37 0.12 2.23 0.063.28 0.14 2.18 0.052.19 0.201.09 0.25Methyl methacrylate-benzene4.68 0.802.34 0.88______________________________________ a φ of perester and peroxide, in the absence of monomer, is assumed as unity; initial concentration of perester or peroxide 2 � 10-2M in each case.
The rates of polymerization of styrene initiated by both the peresters and peroxide are low compared to the decomposition rates of the initiators in the absence of monomer. Moreover, for the same concentration of initiators and monomer, the rate of polymerization with the perester is almost double with the peroxide, although both show near unit quantum yield for decomposition under similar conditions of irradiation in the absence of any monomer.
It has been reported that styrene, and some other vinyl monomers, act as triplet quenchers, the efficiency of quenching depending on the triplet energies of the donor and acceptor. Styrene, having a triplet energy of 62 kcal/mol, can act as a quencher for the benzophenone triplet whose triplet energy is nerely 69 kcal/mol. Styrene drastically reduces the quantum yield of decomposition for both the perester and peroxide, the quenching effect being greater with the peroxide than the perester. Lower values for the quantum yield of decomposition (φrel) for the peroxide probably explains the lower rate of polymerization with it. The difference in the rates of polymerization decreases in the case of methyl methacrylate where the influence of monomer on decomposition of the initiators also is lower.
Table X below illustrates the efficiency of the radicals to initiate polymerization.
The efficiency of the radicals to initiate polymerization, f, in the absence of any appreciable amount of chain transfer, can be defined as ##EQU1## assuming bimolecular termination by the combination of two growing chains only ##EQU2## whereas kd =rate of decomposition of perester in mol/liter sec. in the absence of monomer (a function of light intensity).
The results in Table X show radical efficiency approaches unity at low initiator concentrations by the perester, whereas at higher concentrations of initiator, the apparent efficiency decreases considerably. At higher initiator concentrations, light absorption by the initiator also is high, so the simple kinetic treatment is not valid and, thus, the generation of radicals is no longer proportional to the initiator concentration. This will reflect in apparent lower values of initiator efficiency.
TABLE X______________________________________Radical Efficiency for the Initiation of Polymerizationa Monomer AverageInitiator concen- degree ofconcentration tration Rp � 105 polymer- Radical[I] [M] (mole/ ization efficiency(M � 103) (M) liter sec) -p φrel f______________________________________ Perester-benzene0.31 3.5 0.65 320.4 0.14 0.920.63 3.5 0.92 166.7 0.14 1.211.15 3.5 1.29 155.5 0.14 1.002.52 3.5 1.47 102.8 0.14 0.795.03 3.5 1.72 85.7 0.14 0.568.05 3.5 1.83 77.2 0.14 0.4110.0 2.0 0.95 48.0 0.25 0.1610.0 3.5 1.50 137.2 0.14 0.1510.0 5.0 2.08 219.2 0.12 0.16Perester-chloroform0.14 4.33 1.32 186.01.11 4.33 1.32 186.0 0.14 0.892.28 4.33 1.83 130.0 0.865.14 4.33 2.01 102.9 0.379.92 4.33 2.29 80.5 0.40Peroxide-chloroform5.00 5.88 1.72 372.9 0.08 0.265.00 4.33 1.04 155.8 0.08 0.335.00 3.61 1.07 159.6 0.08 0.33______________________________________ a kd = 5.12 � 10-4 mole/liter sec.
The polystyrene obtained from each of the above polymerizations is purified by repeated (four times) precipitation from benzene solution with methanol. Before each precipitation, the benzene solution is centrifuged to remove any insoluble material. The finely powdered polymer is filtered and dried under vacuum for two days. Known amounts of polymer are dissolved in benzene and the IR is taken (2000-1500 cm-1) against benzene in 0.1-mm NaCl cells. The peaks at 1730 and 1670 cm-1 for the carbonyl groups, caused by ester and benzophenones, respectively, are measured. Thermally polymerized polystyrene (control) shows no absorption in that region. The extinction coefficient of the carbonyl group at 1730 cm-1 is compared with that of authenticated methyl benzoylbenzoate, which is used as a model to measure the concentration of the ester end groups in the polymer. From the concentration of the ester and the extinction resulting from the carbonyl group in the benzophenone, the absorption caused by the benzophenone that is present as the ester can be calculated. The value is subtracted from the absorption obtained at 1670 cm- 1 for the polymer. From the resulting absorption, the concentration of benzophenone alone is estimated from the known extinction of benzophenone at that wavelength.
The results are presented hereinbelow in Table XI.
Except for low monomer concentrations, the total number of benzophenones contained as end groups per chain is almost unity in the case of the perester and almost two in case of the peroxide initiator. Comparison of the benzophenone present as the ester with that of the benzophenone attached by a C--C bond shows that 20-30% decarboxylation occurred. Compared to the decarboxylation of the primary radicals produced from direct irradiation of ordinary peroxides (e.g., benzoyl peroxide) and peresters with a shorter wavelength of λmax, this degree of decarboxylation is small. The low values of benzophenone end groups at low monomer concentration are the result of the effect of chain transfer to monomer or solvent. When the polymers used for end group analysis are from samples obtained from relatively high concentrations of sensitizers (e.g., 10�10-3 M), primary radical termination could not be avoided, in which case, too, the number of benzophenones contained as end groups per chain of polymer should be one for the perester and two for the peroxide.
TABLE XI______________________________________End Group Analysis of Polystyrene StyreneInitiator concen- No. of end groups per chainExperi- concentration tration Benzo-ment [I] � 103 [M] phenone Benzo-No. (M) (M) as ester phenone Total______________________________________I = perester; solvent = benzene1 10 2 0.52 0.18 0.702 10 3.5 0.68 0.13 0.813 10 5.0 0.73 0.33 1.064 10 7.0 0.81 0.18 0.99Perester-Chloroform5 5.0 5.51 0.62 0.29 0.916 5.0 6.92 0.71 0.34 1.05II = Peroxide-Chloroform*7 5.0 3.61 1.29 0.54 1.838 4.52 4.33 1.30 0.62 1.929 4.94 5.88 1.36 0.72 2.08______________________________________ *The peroxide is insoluble in benzene; therefore it was compared to the perester when both are dissolved in chloroform.
Polystyrene obtained from the polymerizations 6 and 9 described in Example 5 above is irradiated at 366 nm in benzene solution containing about 2.5% by volume of secbutyl alcohol and the molecular weights of the resulting polymers are compared with their original molecular weight. The results are reported hereinbelow in Table XII. The increase is higher in the case of peroxide-initiated polymers than it is in the case of perester-initiated polymers, since the former contain an average of two benzophenone groups per chain of polymer initiated by the perester; whereas, half of that is contained in the polymer chains initiated by the perester.
TABLE XII______________________________________Effect of Irradiation of Polystyrene Containing BenzophenoneEnd Groups in the Presence of sec-Butyl AlcoholaExp. No. Initial Molecular weightfrom molecular weight after irradiationExample 5 (--Mn � 10-4) (--Mn � 10-4 )______________________________________6 3.20 4.409 3.41 11.20______________________________________ a Solvent = benzene: contains 2.5% by volume secbutyl alcohol; irradiation time = 3.5 hr at 366 nm.
Some additional discussion of the present invention can be found in Thijs, Gupta and Neckers, Photochemistry of Perester Initiators, J. Organic Chemistry, Vol. 44, No. 23, p. 4123-4128, November 1979, which was written by me and on my behalf, and which disclosure is incorporated herein by reference.
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|Feb 12, 1985
|Bowling Green State University
|Photopolymerizable composition containing perester photoinitiator and photopolymerization process
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|Loctite Corporation
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|Light curable dental composition
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|Novel dialkyl peroxides, production method and use thereof
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|Improvements in or relating to perester compounds
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|U.S. Classification
|560/302, 522/39, 522/33, 549/72, 522/904, 549/60, 544/172, 522/46, 546/226, 546/245, 549/310, 546/225, 549/29, 546/196, 522/34, 544/106, 549/488, 522/60, 544/153
|International Classification
|Cooperative Classification
|European Classification
|Nov 29, 1983
Owner name: BOWLING GREEN STATE UNIVERSITY, BOWLING GREEN, OH.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:NECKERS, DOUGLAS C.;REEL/FRAME:004194/0478
Effective date: 19830721