The invention relates to a display device for displaying visual information, comprising: at least one image-forming element; at least one light source for generating a light beam, which in cooperation with the image-forming element produces an illuminated image; optical means for processing the light beam and/or illuminated image; and a projection surface for receiving the illuminated image, wherein the image-forming element is flat and the projection surface forms at least a part of a cylinder wall.

1. Field of the Invention
The invention relates to a display device for displaying visual information according the preamble of claim 1.
2. Description of Prior Art
In the present information society there is a great need for displaying visual information such as for instance graphic material. Examples of display of visual information are for instance bill boards, information panels, screens and so on. Bill boards usually contain static (printed) information which may or may not take a multiple form in a determined advertising device for changing an advertising text. Information panels with changeable information are usually constructed from displaceable panel parts or individually controllable light pixels. Determined information cast be shown by displacing the panel parts and/or with or without activation of particular light pixels. The resolution of such panels is generally limited and the information they can contain is usually also limited (for instance only numbers and letters). A screen has the advantage that the possibilities for image formation appear virtually unlimited. A drawback here however is that the shape of a screen is substantially flat and either requires a considerable rear construction or has to be illuminated from a distance. The options for use are consequently limited.
The German Offenlegungsschrift DE 195 00 693 shows an advertising and information system with a cylindrical or conical projection surface to be connected with a ceiling. Inside the projection surface a dia or video projector is located. The dia or video projector is directly projecting an image on the projection surface by way of a mirror system. The dia or video projector is placed on a turntable by turning of which the projector can create a going around image on the projection screen.
The present invention has for its object to provide a display device for displaying visual information with which a great freedom in the form of images can be combined with flexibility in changing the images and a high quality of the images.
The invention provides for this purpose a display device for displaying visual information. The optical means preferably comprise at least a reflector which can take the form of at least a part of a conical surface or a pyramid. In addition, it is also possible to use an intermediate form of cone and pyramid, for instance a polygon. With such a display device an illuminated image can be displayed on a continuous way in a random size on a projection surface which has a curved shape of a cylinder shell. The continuous cylindrical projection of the image on the projection surface makes the image steady and more clear then when each part of the projection surface is lighted during only a period of time. Another advantage in relation to the projection device as disclosed in the German Gebrauchsmuster is that the device according the invention has no mechanically moving parts; this makes the device according the invention better in use (less noisy), more reliable and less liable of maintenance. Another advantage of such a projection surface is that it produces a very attractive appearance for a wide variety of applications, and not only for adjustment to a ceiling, such as for instance advertising pillars, video conferencing displays, virtual reality pillars etc. It is noted herein that as desired the inside or the outside is considered as the primary projection surface. In said application as advertising pillar, for instance at large events, fairs, in shopping centres, at stadiums and airports, particularly the outside of a pillar is the relevant projection surface. In an application as virtual reality pillar, use can in contrast be made of the inside of the cylinder wall as projection surface so that a person at least partially surrounded by the cylinder wall surface can undergo the illusion of being in a different environment. An additional option here can consist of embodying, at least a part of the projection surface as so-called xe2x80x98touch screenxe2x80x99, whereby the projected visual information can be changed by touching said screens. Owing to the entirely new concept of displaying visual information such as picture material with the display device according to the invention, many applications will become possible which do not exist at the moment. By embodying the optical means in the form of a reflector, the costs thereof can be limited. With a reflector in the shape of a cone or pyramid a simple construction can moreover be realized in combination with the cylinder wall-shaped projection surface. An additional advantage herein is that with said reflector shapes the distortion of the image created by the image-forming element is controllable.
The reflector is preferably disposed close to an end side surface of the cylinder defining the cylinder wall. By means of this construction a compact display device can be realized the whole cylinder wall of which can be utilized for displaying visual information.
In another preferred embodiment the image-forming element is coupled to a computer for control thereof. The control of the image-forming element enables changing of the projected images as desired. It is thus possible to adapt the visual information to an actual situation. It is also possible to display moving images with the image-forming element. Yet another option of the computerized control is the possibility of compensating the image created by the image-forming element on the optical means When the distortion of the optical means is known, it is possible by means of a standardized process to control the image-forming element such that the projected image acquires the desired form, The distortion of the optical means can thus be compensated by means of a standardized conversion. Yet another advantage of the control by means of computer is that the computer can be programmed by means of cables or a remote receiver such that the desired images are projected. Changing of the images for displaying can thus take place at a distance and makes it unnecessary to go to the display device.
In a preferred embodiment the image-forming element is formed by a light passage screen, such as for instance a display with liquid crystals, also referred to as liquid crystal display (L.C.D.). A variant hereof is referred to as ferro liquid display (F.L.D.). Such a light passage screen is preferably disposed between the light source and the optical means. Such a light passage screen is affordable and obtainable in both black-and-white and colour versions. The display device can be constructed very simply when the light source, for instance a projector, casts a light beam through the light passage screen whereby an illuminated image results which is subsequently directed onto the projection surface by the optical means. Such a display device can be manufactured for a significant part with components which are readily available. In practice the light passage screen will usually be placed in the projector so that it is situated between the light source and the lens of the projector. This solution is moreover compact and easy to install.
In another preferred embodiment the image-forming element is formed by a reflection surface built up of a plurality of parts, which parts can be individually positioned, such as for instance a digital mirroring device (D.M.D.). Such an image-forming element reflects light cast thereon, which reflected light forms an illuminated image. A D.M.D. can also be controlled using a computer. Such image-forming elements are also known under the name of digital light processing (D.L.P.).
The projection surface is preferably manufactured from a transparent material such that an image projected on the inside of the cylinder wall is visible on the outside of the cylinder wall. The image-forming element, the light source and the optical means are herein preferably all disposed substantially in the cylinder defined by the projection surface. Such a display device can be embodied such that the outside is cylindrical without associated components situated on the outside of the cylinder. This provides the display device with an aesthetically attractive appearance and enables use of the display device in a variety of environments. Depending on the choice of material for the cylinder wall and/or the arranging of a protective casing, the display device is vandal-proof. An additional advantage is that the projection means in such a display device take up no space outside the cylinder, which also increases the application possibilities.
In a particular preferred embodiment the display device is provided with a part of a reflecting sphere, via which the light cast by a projector is projected onto a projection surface in the form of a cylinder shell. Very favourable results can be achieved when such a device takes a multiple form in that two mutually facing parts of reflecting spheres are disposed in a projection surface in the form of a cylinder shell and have central openings arranged therein for passage of the light cast by two projectors. With such embodiments favourable results have obtained in practice been achieved in realizing bright images over the whole surface of a cylinder wall.
In order to increase the brightness of the image on the cylinder shell the projection surface is preferably formed by a cylindrical Fresnel lens. Such a construction is characterized by external grooves in the surface of the cylinder shell such that in cross-section a saw tooth-like structure is present with saw teeth mutually connecting in uniform manner. So as to limit the exit angle of the light particularly in vertical direction (i.e. parallel to the axis of the cylinder wall-shaped projection surface) the inner side of the cylindrical Fresnel lens, which is smooth, is covered in a preferred embodiment with a so-called high gain material. This results in more light in the remaining light cone and therefore in a sharper image by for instance a factor of 2. An example of a high gain material is holographic optical diffuser. The light cast by the Fresnel lens impinges on a diffuser screen placed round the lens.
The light from a projector is generally polarized linearly. Because the efficiency of a Fresnel lens is dependent upon polarization, considerable colour variations can occur during deflection of differently polarized light colours at relatively large angles, i.e. in the middle and at the edges of the cylinder shell. In order to eliminate this, use is preferably made of a depolarizing element placed between the projector and the part of the reflecting sphere. Examples hereof are; a xc2xcxcex plate, a wedge depolarizer and a Fresnel rhomb. Such an element provides the same degree of polarization (or the absence thereof) for all light colours, whereby colour variations no longer occur.
For protection purposes an outer cylinder is preferably placed round the projection surface in the form of a cylinder shell formed by the Fresnel lens and the diffuser screen placed therearound. When the inner or outer side of this outer cylinder is provided with a lenticular structure, it is ensured that light originating from the Fresnel lens is distributed from the cylinder shell particularly in a direction perpendicular to the axis, i.e. in horizontal direction when the cylinder is placed vertically.

Display device having a cylindrical projection surface such that an image projected onto the inside is visible on the outside


A system and method for applying an animal access port to an inclined surface, such as an inclined cellar door. The system includes rail elements that are applied to the inclined surface on either side of an opening that has been cut through the inclined surface. The rail elements create tracks along the sides of the opening. A dormer structure is provided. The dormer structure has walls and a top surface that spans the walls to define an interior space within the dormer structure. However, the dormer structure has no bottom surface, and is thus open at its bottom. One of the walls of the dormer structure supports a door. The dormer surface can be placed in the tracks created by the rail elements. The tracks retain the dormer structure in place over the opening in the inclined surface. The dormer structure protects the opening in the inclined surface and provides access to the opening through the door in the wall of the dormer structure.

1. Field of the Invention
The present invention relates to animal access doors of the type that enable a pet dog or cat to enter or exit a building unassisted. More particularly, the present invention relates to the structure of animal access doors and the methods of installing such animal access doors to different surfaces.
2. Description of the Prior Art
The prior art record is replete with different types of animal access doors. The simplest animal access doors are just small openings that are cut through the door or wall of a house so that a dog or cat can enter or exit the house at will. The cut opening is typically covered by a flap that can be swung open by the pet as the pet passes through the opening. A problem associated with such swinging flap animal access doors is that they enable strange animals or wild animals access to the house. Furthermore, such swinging door access openings do little to keep out bad weather and wind. Rather, such swinging flap animal access doors rely upon their vertical orientation to keep the flap closed and the weather out. Consequently, such swinging flap animal access doors are typically applied to house doors that have some type of overhang protection to keep weather from directly bearing on the surface of the door.
To help prevent strange animals or wild animals from entering animal access doors, high-tech animal access doors have been developed. Such high-tech animal access doors only open or unlock when a specific pet approaches the animal access door. Such animal access doors contain sensors that detect a magnet or signal emitter that is carried on the collar of the pet. As the pet approaches the door, the collar on the pet is detected and the animal access door briefly opens or unlocks. Such prior art animal access doors are exemplified by U.S. Pat. No. 4,991,350, to Kirk, entitled Electromagnetically Controlled Cat Flap.
Since very few pets are trained to close doors, both hanging flap access doors and high tech access doors typically rely upon gravity to close the door after the animal has passed. Consequently, such animal access doors must be applied to vertical surfaces so that gravity will return the animal access door to a vertical position. However, there are many surfaces in a house that are not vertical. One such surface is an inclined cellar door. Inclined cellar doors are typically used to cover external stairways that lead directly to the cellar of a home from the outside. Inclined cellar doors are popular with many homeowners because they provide a large access port to the cellar that enables large objects, such as boilers, water heaters, pool tables and the like to be more readily moved into and out of the cellar.
Many pet owners keep their pets in their cellars. It would be highly desirable for a home to have a pet access door that leads directly from the cellar to the outside. However, conventional animal access doors cannot be applied to inclined cellar doors. If they were, they would not close and would allow weather and strange animals to enter the cellar. Furthermore, the unclosed animal access door at the top of the cellar stairwell would present a falling hazard to children and unwary animals.
A need therefore exists for a new animal access door that is adapted to be applied to an inclined surface, such as an inclined cellar door, wherein the animal access door keeps out the weather and does not present a falling hazard. This need is met by the present invention as described and claimed below.
The present invention is a system and method for applying an animal access port to an inclined surface, such as an inclined cellar door. The system includes rail elements that are applied to the inclined surface on either side of an opening that has been cut through the inclined surface. The rail elements create tracks along the sides of the opening. A dormer structure is provided. The dormer structure has walls and a top surface that spans the walls to define an interior space within the dormer structure. However, the dormer structure has no bottom surface, and is thus open at its bottom. One of the walls of the dormer structure supports a door. The dormer surface can be placed in the tracks created by the rail elements. The tracks retain the dormer structure in place over the opening in the inclined surface. The dormer structure protects the opening in the inclined surface and provides access to the opening through the door in the wall of the dormer structure.
The dormer structure can be selectively removed from the track of the rail elements. In its place, a solid plate can be positioned, using the track of the rail elements. The result is a solid cover that protects the opening in the inclined surface from any access.

System and method for applying an animal access door to an inclined surface


A multipurpose hemofiltration system and method are disclosed for the removal of fluid and/or soluble waste from the blood of a patient. The system and method are equally applicable to adult, pediatric and neonatal patients. In one embodiment, the system continuously monitors the weight of infusate in a first reservoir and drained fluid in a second reservoir and compares those weights to corresponding predetermined computed weights. When necessary, the pumping rates of the infusate, drained fluid and blood are adjusted in order to achieve a preselected amount of fluid removal from the patient""s blood in a preselected time period. Application of this system and method provide repeatable and highly precise results. Alternatively, predetermined patient parameters can be monitored and the adjustment of pumping rates may be responsive to these monitored parameters. Suitable patient parameters are arterial pressure, central venous pressure, pulmonary arterial pressure, mean arterial pressure, capillary wedge pressure, systemic vascular resistance, cardiac output, mixed venous O2 saturation, arterial O2 saturation, blood pressure, heart rate, patient weight, and hematocrit.

The present invention is directed to a system and method of blood filtration, and more particularly a continuous system and method for the regulation of the rate of filtration of fluid and/or soluble waste from the blood of a patient based on one or more monitored patient parameters.
For various reasons, including illness, injury or surgery, patients may require replacement or supplementation of their natural renal function in order to remove excess fluid or fluids containing dissolved waste products from their blood. Several procedures known for this purpose are dialysis, hemodialysis, hemofiltration, hemodiafiltration and ultrafiltration; another related procedure is plasmapheresis. The specific procedure employed depends upon the needs of the particular patient. For example, dialysis is used to remove soluble waste and solvent from blood; hemofiltration is used to remove plasma water from blood; hemodiafiltration is used to remove both unwanted solute (soluble waste) and plasma water from blood; ultrafiltration is a species of hemofiltration; and plasmapheresis is used to remove blood plasma by means of a plasmapheresis filter. Because the replacement of renal function may affect nutrition, erythropoiesis, calcium-phosphorus balance and solvent and solute clearance from the patient, it is imperative that there be accurate control of the procedure utilized. The accurate control of the rate of removal of intravascular fluid volume is also important to maintain proper fluid balance in the patient and prevent hypotension.
Various systems have been proposed to monitor and control renal replacement procedures. For example, U.S. Pat. No. 4,132,644 discloses a dialysis system in which the weight of dialyzing liquid in a closed liquid container is indicated by a scale. After the dialyzing liquid flows through the dialyzer, the spent liquid is returned to the same container and the weight is again indicated. Since the container receives the original dialyzing liquid plus ultrafiltrate, the amount of ultrafiltrate removed from the patient is equal to the increase in total weight in the container. This system is not driven by a weight measuring device and does not offer precise control of the amount of liquids used in the procedure.
U.S. Pat. No. 4,204,957 discloses an artificial kidney system which utilizes weight measurement to control the supply of substitute fluid to a patient. In this system, the patient""s blood is pumped through a filter and the filtrate from the blood is discharged to a measuring vessel associated with a weighing device. A second measuring vessel containing substitute fluid is associated with a second weighing device and is connected to the purified blood line. By means of a pump, the substitute fluid and the purified blood are pumped back to the patient. The first and second weighing devices are coupled to one another by a measuring system in such a way that a fixed proportion of substitute is supplied to the purified blood stream from the second measuring vessel depending an the weight of the filtrate received in the first measuring vessel. This system does not utilize circulating dialysate fluid in the blood filtration.
U.S. Pat. No. 4,767,399 discloses a system for performing continuous arteriovenous hemofiltration (CAVH). The disclosed system relies upon utilizing a volumetric pump to withdraw a desired amount of fluid from the patient""s blood and return a selected amount of fluid volume to the patient.
U.S. Pat. No. 4,923,598 discloses an apparatus for hemodialysis and hemofiltration which comprises an extracorporeal blood circuit including a dialyzer and/or filter arrangement. The system determines fluid withdrawal per unit time and total amount of fluid withdrawn by utilizing flow sensors in conjunction with an evaluating unit located upstream and downstream of the dialyzer or filter arrangement in the blood circuit.
U.S. Pat. No. 4,728,433 discloses a system for regulating ultrafiltration by differential weighing. The system includes a differential weighing receptacle having an inlet chamber and an outlet chamber which allows a fixed amount of fresh dialysate, by weight, to flow through the hemodialyzer. This system operates in a sequence of weighing cycles during which the amount of ultrafiltrate removed from the blood may be calculated. Additionally, the ultrafiltration rate for each weighing cycle may be calculated. This system provides a mechanism for determining and regulating the amount of ultrafiltrate removed from the blood while delivering dialysate to the patient in alternating fill and drain cycles of the inlet and outlet chambers of the differential weighing receptacle.
The need exists for a multipurpose renal function replacement/supplementation system which is accurate, reliable, capable of continuous, long-term operation, and which can be used effectively on adult, pediatric and neonatal patients.
The present invention is directed to a multipurpose system and method for removal of fluid and/or soluble waste from the blood of a patient: ultrafiltration only, hemodiafiltration, hemodiafiltration and ultrafiltration, and plasmapheresis with or without fluid replacement. The system and method of the present invention can provide reliable, long term operation (5-10 days) with a great degree of accuracy (on the order of +xe2x88x922 grams regardless of the total volume of fluid passing through the system). The system and method of the invention are advantageous because of the multipurpose nature thereof, the repeatability and accuracy of the processes, and the simultaneous, continuous flow of fluids in an extracorporeal blood circuit, while being equally applicable to adult, pediatric and neonatal patients.
As used herein the term xe2x80x9chemofiltrationxe2x80x9d is to be broadly construed to include hemodialysis, hemofiltration, hemodiafiltration, ultrafiltration and plasmapheresis processes. As used herein, the term xe2x80x9cinfusatexe2x80x9d is defined to include dialysate fluid or any other replacement fluids which may be supplied to the patient as a part of the hemofiltration procedures.
In a preferred embodiment, the system of the present invention includes a hemofilter, a blood pump for pumping blood from a patient through the hemofilter and back to the patient, and suitable tubing for carrying the pumped blood to and from the patent. The system further includes a first reservoir for maintaining a supply of infusate, a first weighing means for continuously monitoring the weight of the infusate and generating weight data signals correlated to the monitored weight, and a first pump for pumping the infusate from the first reservoir to the hemofilter or appropriate blood tubing access port. A second reservoir receives drained fluid (e.g., spent infusate or ultrafiltrate, including the fluids and solutes removed from the blood) from the hemofilter, and a second weighing means monitors the weight of the drained fluid and generates weight data signals correlated to the monitored weight. A second pump pumps the drained fluid from the hemofilter to the second reservoir. The system also includes a computerized controller operably connected to the blood pump, the infusate pump, the drain pump and the first and second weighing means.
The controller periodically, but on an ongoing basis during the treatment, interrogates at predetermined intervals the weight data signals that are continuously generated by the first and second weighing means and is designed to determine therefrom the weight of infusate and drained fluid in the first and second reservoirs at the predetermined intervals. The rate of fluid withdrawal from the blood is also determined. The controller compares the infusate and drained fluid weights to corresponding predetermined computed weights in the memory of the controller, and, when necessary, the controller generates control signals which automatically adjust the pumping rates of the infusate and drained fluid pumps in order to achieve a preselected amount of fluid removal from the patient""s blood. Additionally, the controller is programmed to operate the infusate and drained fluid pumps only when the blood pump is operating. Furthermore, the blood pump is operably connected to and is responsive to control signals generated by the controller in response to or independent of the weight data signals to vary the flow rate of the blood through the hemofilter as required to achieve the desired level of fluid removal from the blood.
In an alternative embodiment, the computer controller is, by initial selection of the operator, interfaced with one or more of the various monitoring systems that are operably connected to the patient. These monitoring systems, which are well known in the art, generate and output data signals corresponding to the monitored patient parameters, and the computer controller receives such data signals. During the hemofiltration operation, the interfaced parameters are constantly monitored; however, the controller only responds to specific parameter data that corresponds to the patient parameters selected by the operator. The patient parameters which may be monitored and interfaced with the computer controller include the following: arterial pressure, central venous pressure, pulmonary arterial pressure, mean arterial pressure, capillary wedge pressure, systemic vascular resistance, cardiac output, O2 saturation (mixed venous or arterial), blood pressure, heart rate, patient weight, external infusion rates, and hematocrit. Numerous of these parameters may be monitored and corresponding output data signals generated in known manner utilizing an indwelling intravenous or intra-arterial catheter. The remaining parameters are monitored and data signals are generated by means well known in the art. The operator will select one or more of the above parameters to interface with the controller which will then periodically, but on an ongoing basis during treatment, interrogate at predetermined intervals the parameter data signals that are continuously generated by the interfaced monitoring system(s). The controller then evaluates the parameter data and in response thereto, when necessary, the controller generates control signals which automatically adjust the pumping rates of the infusate, drained fluid and blood pumps so as to achieve a preselected amount of fluid removal from the patient""s blood.
It will be appreciated that the system of the present invention may utilize a combination of monitoring and responding to the infusate and drained fluid weight data signals, as described in connection with the first embodiment hereinabove, along with one or more of the other patient parameters interfaced to the controller.
By way of specific examples, in connection with monitoring the patient""s weight, the computer controller may be interfaced with a bed scale which provides continuous values for the patient""s weight. In response to the overall patient weight data signals, the computer controller may control the infusate and/or drained fluid pumps to achieve a predesigned protocol for decreasing or increasing the patient""s weight over time. The change in patient""s weight (by increase or decrease) can be accomplished in either a linear or non-linear (such as curvilinear) manner with respect to time by appropriate pump control. Similarly, the computer may be interfaced with a continuous read-out device of the patient""s O2 saturation and the controller will receive, evaluate and respond to the O2 saturation data by controlling the infusate, drained fluid and blood pumping rates accordingly.
In connection with all of the above-described monitored parameters, the computer controller will receive data signals corresponding and relating to each particular selected parameter from an appropriate signal generating device or source operably connected to the patient. The controller will then, after periodic interrogation, compare the interrogated values with predetermined desired values and will automatically make the appropriate, predetermined changes in the infusate, drained fluid and blood pumping rates in response to the monitored signals. Furthermore, more than one of the above-referenced parameters can be continuously monitored simultaneously and the computer may be programmed with a hierarchy to consider one or more specific parameters rather than others and will respond with the appropriate and desired adjustments in infusate, drained fluid and blood pumping rates based on those selected parameters.
The computer controller is designed and programmed to adjust the pumping rates (pump speed) of the infusate, drained fluid and blood pumps so as to provide a linear response or a non-linear (curvilinear) response to the observed changes in the selected monitored parameters. In this regard, xe2x80x9clinearxe2x80x9d is defined to mean a fixed, non-exponential change, and xe2x80x9cnon-linearxe2x80x9d or xe2x80x9ccurvilinearxe2x80x9d means anything other than linear. The selection of linear versus non-linear response profile is made by the operator of the system depending on the needs of the patient. For example, in certain situations it may be desirable to have an initially fast fluid removal rate that decreases over time. In that case a curvilinear or exponential response would be utilized. In other circumstances, consistent or constant fluid removal over time is desired, and so a linear response profile is selected. It is further contemplated that at the election of the operator the computer controller may combine linear and curvilinear response signals so as to tailor the pump rates to achieve a desired response profile. For example, a non-linear initial response period for fast initial fluid removal, followed by a linear response period for ongoing fluid removal at a consistent rate.
In yet another alternative embodiment, the computer controller receives data signals from one or more patient infusion pumps that are otherwise independent of the hemofiltration system. These infusion pumps are used for infusion to the patient of intravenous fluids, medications, parenteral nutrition and/or blood products. By monitoring the data output from the independent infusion pumps, the extraneous total fluid volume per unit time may be ascertained. The controller will then, as required, change the pumping rates of the system infusate, drained fluid and blood pumps, as necessary, so as to alter the ultrafiltration rate and/or infusate fluid rate automatically in response to changes in intravenous fluid therapy. This facilitates independent patient management while hemofiltration is being performed. Proper coordination of the controller with the independent infusion pumps allows the desired or targeted fluid removal goals by hemofiltration to be achieved automatically in concordance with ongoing intravenous fluid therapy.
In a preferred embodiment of the method of the present invention, blood from a patient is pumped through a hemofilter and a supply of infusate, which is maintained in a first reservoir, is pumped from the first reservoir through the hemofilter, countercurrent to the blood. The weight of infusate in the first reservoir is continuously monitored and data signals correlated to that weight are generated. Drained fluid (e.g., spent infusate) is pumped from the hemofilter and is received in a second reservoir. The weight of the drained fluid in the second reservoir is continuously monitored and weight data signals correlated thereto are generated. The signals correlated to the weight of infusate and drained fluid are interrogated at regular intervals (for example every minute) by a system controller and are compared to corresponding predetermined computed weights in the memory of the controller. The controller determines the amount and rate of fluid withdrawal from the patient""s blood. If those values differ from preselected, preprogrammed desired values, the controller generates control signals which independently adjust the pumping rates of the infusate and drained fluid pumps so as to achieve the desired amount of fluid removal. The control signals may also control the blood pumping rate.
In an alternative embodiment of the method of the present invention, independent of or in addition to the infusate and drained fluid weight monitoring and pump control, the computer controller may be interfaced with one or more of the previously discussed monitoring systems. In this embodiment, the controller will receive, evaluate and respond to the selected patient parameter data by generating appropriate, responsive control signals by which the infusate, drained fluid and blood pumping rates are controlled to achieve the desired amount of fluid removal. This may be accomplished in combination with or independent of the infusate and drained fluid weight monitoring.
The advantages of the system and method of the present invention are achieved at least in part due to the continuous monitoring and periodic interrogation of the fluid weights, and other selected patient parameters, and the adjustment of fluid pumping rates in response thereto, including the blood pumping rate, so as to achieve ideal or nearly ideal fluid removal and replacement if necessary from a patient""s blood. Further features and advantages of the system and apparatus of the present invention will become apparent with reference to the Figure and the detailed description which follows.

Hemofiltration system and method based on monitored patient parameters


A s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonatte and derivatives thereof can be used as an initiator, chain transfer agent, or terminator for polymerization of monomers such as free radical polymerizable monomers. Homopolymers, copolymers, and the like as well as block copolymers can be made utilizing the trithio carbonate compound such as in a living free radical polymerization as well as to form telechelic polymers.

The present invention relates to s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonates and derivatives thereof, as well as a process for making the same. Moreover, other functional end groups can be derived from the carboxylic acid end groups. The compounds can be utilized as initiators, chain transfer agents, or terminators for controlled free radical polymerizations. Free radical polymerizations utilizing s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds generally form telechelic polymers. If an initiator other than the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound is also utilized, a polymer having a single functional end group is formed in proportion to the amount of the initiator to the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound utilized.
Although several members of the class of organic thiocarbonates have been known for many years and various routes have been employed for their synthesis, the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention have not been disclosed. Trithiocarbonate compounds have been claimed for various applications, such as pesticides for agriculture, and also as lubricating oil additives.
Traditional methods of producing block copolymers, such as by living polymerization or the linking of end functional polymers, suffer many disadvantages, such as the restricted type monomers which can be utilized, low conversion rates, strict requirements on reaction conditions, and monomer purity. Difficulties associated with end linking methods include conducting reactions between polymers, and problems of producing a desired pure end functional polymer. The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention can alleviate the above noted problems and difficulties when utilized in free radical polymerizations.
The prior art WO98/01478 reference discloses the use of thiocarbonates to conduct living free radical polymerizations. The reference is limited to alkyl and benzyl functional groups, and is unable to make any aryl or carboxylic acid substituted trithiocarbonates with general methods known to the art. Synthesis, p 894 (1986), J. Chemical Research (Synopsis), p478 (1995), and Synthetic Communications, Vol. 18, p 1531 (1988). We have also found the conversion for the dibenzyl derivatives disclosed in their example 26 to be very slow compared to the present invention when polymerizing acrylate, as can be seen in the Example section of this application.
The present invention relates to s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonates which have the general formula:
where R1 and R2 are set forth below, to derivatives thereof, and to a process for making the same.
The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid) trithiocarbonate compounds can generally be formed from carbon disulfide, a haloform, and a ketone in a strong base, such as sodium hydroxide, followed by acidification. The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid) trithiocarbonate compounds can be used as inifertors, i.e. as initiators and chain transfer agents, and/or chain terminators or as a chain-transfer agent during polymerization. The compounds can thus be utilized to control free radical polymerization thermally and chemically to give narrow molecular weight distributions. Polymerization of monomers can be in bulk, in emulsion, or in solution. Block copolymers can be made if two or more monomers are polymerized in succession. The difunctional acid end groups present can further react with other reactive polymers or monomers to form block or random copolymers. Free radical polymerizations utilizing the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds generally form telechelic polymers. If an initiator other than the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound is also utilized, a polymer having a single functional end group is formed in proportion to the amount of said other initiator to the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound utilized.
The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate and derivatives prepared by the processes disclosed later herein generally can be described by the formula:
wherein R1 and R2, independently, can be the same or different, and can be linear or branched alkyls having from 1 to about 6 carbon atoms, or a C1 to about C6 alkyl having one or more substituents, or one or more aryls or a substituted aryl group, having 1 to 6 substituents on the aryl ring, where the one or more substituents, independently, comprise an alkyl having from 1 to 6 carbon atoms; or an aryl; or a halogen such as fluorine or chlorine; or a cyano group; or an ether having a total of from 2 to about 20 carbon atoms such as methoxy, or hexanoxy; or a nitro; or combinations thereof. Examples of such compounds include s,sxe2x80x2-bis-2-methyl-2-propanoic acid-trithiocarbonate and s,sxe2x80x2-bis-(2-phenyl-2-propanoic acid)-trithiocarbonate. R1 and R2 can also form or be a part of a cyclic ring having from 5 to about 12 total carbon atoms. R1 and R2 are preferably, independently, methyl or phenyl groups.
The abbreviated reaction formula for the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonates of the present invention can be generally written as follows:
The process utilized to form the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention is generally a multi-step process and includes combining the carbon disulfide and a base whereby an intermediate trithio structure is formed, see I, II, III, and IV. Ketone can serve as solvent for the carbon disulfide/base reaction and thus can be added in the first step of the reaction. In the second step of the reaction, the haloform, or haloform and ketone, or a xcex1-trihalomethyl-xcex1-alkanol are added to the trithio intermediate mixture and reacted in the presence of additional base, see V, VI, and VII. The formed reaction product, see IX, is subsequently acidified, thus completing the reaction and forming the above described s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound, see X.
The reaction is carried out at a temperature sufficient to complete the interaction of the reactants so as to produce the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound in a desired time. The reaction can be carried out at any temperature within a wide range from about the freezing point of the reaction mass to about the reflux temperature of the solvent. The reaction temperature is generally from about minus 15xc2x0 C. to about 80xc2x0 C., desirably from about 0xc2x0 C. to about 50xc2x0 C., and preferably from about 15xc2x0 C. to about 35xc2x0 C., with room temperature being preferred. The reaction can be performed at atmospheric pressure. The reaction time depends upon several factors, with the temperature being most influential. The reaction is generally complete within 20 hours and preferably within 10 hours.
A phase transfer catalyst is preferably utilized if a solvent is used in the reaction. Examples of solvents are set forth herein below. The ketone utilized in the reaction may double as a solvent, and therefore no catalyst usually is needed. The amount of phase transfer catalyst, when utilized in the present invention, is generally from about 0.1 mole percent to about 10 mole percent, desirably from about 0.5 mole percent to about 5 mole percent and preferably from about 2 mole percent to about 4 mole percent per mole of carbon disulfide. The phase transfer catalysts can be polyether, and/or an onium salt including a quaternary or tertiary organic compound of a group VA or VIA element of the Periodic Table and salts thereof. Most preferred are quaternary amines, and salts thereof.
xe2x80x9cOnium saltsxe2x80x9d more particularly refer to tertiary or quaternary amines and salts such as are generally used in the phase transfer catalysis of heterogeneous reaction in immiscible liquids. The general requirement for the onium salt chosen is that it be soluble in both the organic and aqueous phases, when these two liquid phases are present, and usually a little more soluble in the organic phase than the aqueous phase. The reaction will also proceed with a phase transfer catalyst when there is only a single organic liquid phase present, but such a reaction is less preferable than one in which both aqueous and organic liquid phases are present. A wide variety of onium salts is effective in this ketoform synthesis.
The onium salts include the well-known salts, tertiary amines and quaternary compounds of group VA elements of the Periodic Table, and some Group VIA elements such as are disclosed in the U.S. Pat. No. 3,992,432 and in a review in Angewandte Chemie, International Edition in English, 16 493-558 (August 1977). Discussed therein are various anion transfer reactions where the phase transfer catalyst exchanges its original ion for other ions in the aqueous phase, making it possible to carry our chemistry there with the transported anion, including OH-ions.
The onium salts used in this synthesis include one or more groups having the formula (RnY)+Xxe2x88x92, wherein Y is either a pentavalent ion derived from an element of Group VA, or a tetravalent ion derived from an element of Group VIA; R is an organic moiety of the salt molecule bonded to Y by four covalent linkages when Y is pentavalent, and three covalent linkages when Y is tetravalent; Xxe2x88x92 is an anion which will dissociate from the cation (RnY)+ in an aqueous environment. The group (RnY)+Xxe2x88x92 may be repeated as in the case of dibasic quaternary salts having two pentavalent Group VA ions substituted in the manner described.
The preferred onium salts for use in the invention have the formula
(RARBRCRDY+)Xxe2x88x92
wherein Y is N or P, and R1-R4 are monovalent hydrocarbon radicals preferably selected from the group consisting of alkyl, alkenyl, aryl, alkaryl, aralkyl, and cycloalkyl moieties or radicals, optionally substituted with suitable heteroatom-containing functional groups. The onium salts are generally selected to be less preferentially less soluble in the less. polar of the two distinct liquid phases. Any of the salts disclosed in the U.S. Pat. No. 3,992,432 will be found effective, but most preferred are those in which the total number of carbon atoms in RA,RB, RC, and RD cumulatively range from about 13 to about 57, and preferably range from about 16 to about 30. Most preferred onium salts have Y=N, and hydrocarbon radicals where RA is CH3, and RB, RC, and RD are each selected from the group consisting of nxe2x80x94C2H5, nxe2x80x94C4H5; nxe2x80x94C5H11; mixed C5H17; nxe2x80x94C12H25; nxe2x80x94C18H37; mixed C8-C10 alkyl; and the like. However, RA may also be selected from C2H5nxe2x80x94C3H7 and nxe2x80x94C4H9 benzyl.
Various counterions may be used, including Clxe2x88x92, Brxe2x88x92, Ixe2x88x92, NO3xe2x88x92, SO4xe2x88x922, HSO4xe2x88x92 and CH2CO2xe2x88x92. Most preferred is Clxe2x88x92.
The tertiary amines or triamines useful as phase transfer catalysts in this synthesis include the alkyl amines and the aryldialkylamines, exemplified by tributylamine and phenyldibutylamine respectively, which are commonly available, wherein each alkyl may have from 1 to about 16 carbon atoms.
The polyethers useful as catalysts in this synthesis include cyclic polyethers such as the crown ethers, disclosed in Agenwandte Chemie, supra, and acyclic polyethers having the formula
Rxe2x80x94Oxe2x80x94RE
wherein R and RE are, independently, alkyls having from 1 to about 16 carbon atoms, or alkyl containing substituted functional groups such as hydroxy, sulfur, amine, ether, etc. Most preferred acyclic polyethers have the formula
xe2x80x83Rxe2x80x94(OCH2CH2),ORxe2x80x3
wherein
R is an alkyl having from 1 to about 16 carbon atoms
Rxe2x80x3 is an alkyl having from 1 to about 16 carbon atoms, or H, and
r is an integer in the range from 0 to about 300.
Most preferred are commonly available polyethers such as: tetraethylene glycol dimethyl ether; polyethylene oxide (mol wt. About 5000); poly(ethylene glycol methyl ether); 1,2-dimethoxyethane; diethyl ether, and the like.
Polyether catalysts are especially desirable in this ketoform synthesis because they are directive so as to produce a preponderance of the desired symmetrically substituted isomer, in a reaction which is remarkably free of undesirable byproducts, which reaction proceeds with a relatively mild exotherm so that the reaction is controllable.
The organic solvent may be any solvent in which the reactants are soluble and include hydrohalomethylenes, particularly hydrochloromethylenes, sulfolane, dibutyl ether, dimethyl sulfone, diisopropyl ether, di-n-propyl ether, 1,4-dioxane, tetrahydrofuran, benzene, toluene, hexane, carbon tetrachloride, heptane, mineral spirits and the like. Most preferred solvents are heptanes and mineral spirits. Solvent is generally utilized in an amount generally from about 10 to about 500 percent and preferably from about 50 percent to about 200 percent based on the total weight of the reactants.
Insofar as the reactive components are concerned, any of various ketones having the general formula:
can be employed in the synthesis, wherein R1 and R2 are described herein above. As carbon disulfide is the controlling agent in the reaction, the ketone is generally used in an amount from about 110 mole percent to about 2,000 mole percent per mole of carbon disulfide. When the ketone is used as a solvent, it is generally utilized in an amount of from about 150 mole percent to about 300 mole percent, and preferably from about 180 mole percent to about 250 mole percent per mole of carbon disulfide.
The alkali bases suitable for use in the synthesis of the present invention include, but are not limited to, sodium hydroxide and potassium hydroxide. The base is utilized in an amount generally from about 5 times to about 15 times the number of moles of carbon disulfide and preferably from about 6 to about 10 times the number of moles of carbon disulfide utilized in the reaction.
The acids used in the acidification step include, but are not limited to, hydrochloric acid, sulfuric acid, phosphoric acid, etc. The acids are utilized in amounts suitable to make the aqueous solution acidic.
The haloform of the present invention has the general formula CHX3 wherein X is, independently, chlorine or bromine. The amount of haloform used in the present invention is generally from about 110 mole percent to about 2000 mole percent, desirably from about 150 mole percent to about 300 mole percent, and preferably 180 mole percent to about 250 mole percent per mole of carbon disulfide. Examples of haloforms include, but are not limited to, chloroform and bromoform, and chloroform is the preferred haloform of the present invention.
Alternatively, instead of adding both a haloform and a ketone, to the reaction mixture, an xcex1-trihalomethyl-xcex1-alkanol can be substituted therefore. The amount of xcex1-trihalomethyl-xcex1-alkanol utilized in the reaction generally is from about 110 mole percent to about 2000 mole percent, desirably is from about 150 mole percent to about 300 mole percent, and preferably is from about 180 mole percent to about. 250 mole percent per mole of carbon disulfide. The general formula of the xcex1-trihalomethyl-xcex1-alkanol is generally represented as follows:
wherein X, R1 and R2 are defined above.
While not wishing to be limited to any particular mechanism, it is believed that the specific mechanism for the reaction process is as follows:
Initially, the carbon disulfide and sodium hydroxide are reacted.
In the subsequent step of the reaction, the chloroform is reacted with the ketone as follows:
Then, the following is reacted:
The overall reaction is as follows:
The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds produced by the present invention can generally be classified as inifertors, meaning that they act as both a chain transfer agent and an initiator. The use of other types of inifertors for block copolymers was discussed by Yagei and Schnabel in Progress in Polymer Science 15, 551 (1990) and is hereby fully incorporated by reference.
Thus, the compounds of the present invention can be utilized as initiators to initiate or start the polymerization of a monomer. They can also act as a chain transfer agent, which interrupts and terminates the growth of a polymer chain by formation of a new radical which can act as a nucleus for forming a new polymer chain. The compounds can.also be utilized as terminators in that when most of initiating radicals and monomers are consumed, the compounds are incorporated in the polymers as a dormant species. Desirably though, another compound, such as those listed herein below, is often used as an initiator in the free radical polymerization process as described herein below, and the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention will act as a chain-transfer agent.
The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention can be used as chain transfer agents in a free radical polymerization process to provide polymerizations which have living characteristics and polymers of controlled molecular weight and low polydispersity, as well as for forming telechelic polymers.
A living polymerization is a chain polymerization which proceeds in the absence of termination and chain transfer. The following experimental criteria can be utilized to diagnose a living polymerization.
1. Polymerization proceeds until all monomer has been consumed. Further addition of monomer results in continued polymerization.
2. The number average molecular weight, Mn (or Xn, the number average degree of polymerization), is a linear function of conversion.
3. The number of polymer molecules (and active centres) is constant and independent of conversion.
4. The molecular weight can be controlled by the stoichiometry of the reaction.
5. Narrow molecular weight distribution polymers are produced.
6. Chain-end functionalized polymers can be prepared in quantitative yields.
7. In radical polymerization, the number of active end groups should be 2, one for each end.
Besides those mentioned above, other criteria can also help to determine the living character ofxe2x80x2polymerization. For radical living polymerization, one is the ability of the polymer isolated from the first step of polymerization to be used as a macroinitiator for the second step of a polymerization in which block copolymers or grafted polymers are ultimately formed. To confirm the formation of block copolymers, measurements of molecular weights and a determination of the structure of the blocks are employed. For structure measurements, the examination of NMR or IR signals for the segments where individual blocks are linked together and a determination of the end groups are both very important. In radical polymerization, only some of the criteria for living polymerizations are actually fulfilled. Due to their ability to undergo further polymerization, these types of polymers can also be called xe2x80x98reactive polymersxe2x80x99. A more detailed description of living polymerization can be found in xe2x80x9cLiving Free-Radical Block Copolymerization Using Thio-Inifertorsxe2x80x9d, by Anton Sebenik; Progress in Polymer Science, vol. 23, p. 876, 1998.
The living polymerization processes can be used to produce polymers of narrow molecular weight distribution containing one or more monomers sequences whose length and composition are controlled by the stoichiometery of the reaction and degree of conversion. Homopolymers, random copolymers or block polymers can be produced with a high degree of control and with low polydispersity. Low polydispersity polymers are those with polydispersities that are significantly less than those produced by conventional free radical polymerization. In conventional free radical polymerization, polydispersities (polydispersity is defined as the ratio of the weight average to the number average molecular weight Mw/Mn) of the polymers formed are typically greater than 2.0. Polydispersities obtained by utilizing the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds and derivatives thereof of the present invention are preferably 1.75 or 1.5, or less, often 1.3 or less, and, with appropriate choice of the chain transfer agent and the reaction conditions, can be 1.25 or less.
When the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonates compounds are utilized only as chain-transfer agents, the polymerization can be initiated with other initiators at lower temperature while yielding polymers with similarly controlled fashion.
Free radical polymerizations utilizing the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds as both initiators and chain transfer agents generally form telechelic polymers. When an initiator other than the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound is also utilized, a polymer having a single functional end group is formed in proportion to the amount of said other initiator to this s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound utilized.
The free radical living polymerization process of the invention can be applied to any monomers or monomer combinations which can be free-radically polymerized. Such monomers include one or more conjugated diene monomers or one or more and vinyl containing monomers, or combinations thereof.
The diene monomers have a total of from 4 to 12 carbon atoms and examples include, but are not limited to, 1,3-butadine, isoprene, 1,3-pentadiene, 2,3-dimethyl-1-3-butadeine, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2-phenyl-1,3-butadiene, and 4,5-diethyl-1,3-octadiene, and combinations thereof.
The vinyl containing monomers have the following structure:
where R3 comprises hydrogen, halogen, C1 to C4 alkyl, or substituted C1-C4 alkyl wherein the substituents, independently, comprise one or more hydroxy, alkoxy, aryloxy(OR5), carboxy, acyloxy, aroyloxy(O2CR5), alkoxy-carbonyl(CO2R5), or aryloxy-carbonyl; and R4 comprises hydrogen, R5, CO2H, CO2R5, COR5, CN, CONH2, CONHR5, O2CR5, OR5, or halogen. R5 comprises C1 to C18 alkyl, substituted C1-C18 alkyl, C2-C18 alkenyl, aryl, heterocyclyl, aralkyl, or alkaryl, wherein the substituents independently comprise one or more epoxy, hydroxy, alkoxy, acyl, acyloxy, carboxy, (and salts), sulfonic acid (and salts), alkoxy- or aryloxy-carbonyl, sicyanato, cyano, silyl, halo and dialkylamino. Optionally, the monomers comprise maleic anhydride, N-alkylmaleimide, N-arylmaleimide, dialkyl fumarate and cyclopolymerizable monomers. Monomers CH2=CR3R4 as used herein include C1-C8 acrylates and methacrylates, acrylate and methacrylate esters, acrylic and methacrylic acid, styrene, cc methyl styrene, C1-C12 alkyl styrenes with substitute groups both either on the chain or on the ring, acrylamide, methacrylamide, and methacrylonitrile, mixtures of these monomers, and mixtures of these monomers with other monomers. As one skilled in the art would recognize, the choice of comonomers is determined by their steric and electronic properties. The factors which determine copolymerizability of various monomers are well documented in the art. For example, see: Greenley, R. Z., in Polymer Handbook, 3rd Edition (Brandup, J., and Immergut, E. H. Eds.) Wiley: N.Y., 1989 pll/53.
Specific monomers or comonomers include the following: methyl methacrylate, ethyl methacrylate, propyl methacrylate (all isomers), butyl methacrylate (all isomers), 2-ethylhexyl methacrylate, isobornyl methacrylate, methacrylic acid, benzyl methacrylate, phenyl methacrylate, methacrylonitrile, alpha-methylstyrene methyl acrylate, ethyl acrylate, propyl acrylate (all isomers), butyl acrylate (all isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid, benzyl acrylate, phenyl acrylate, acrylonitrile styrene, functional methacrylates, acrylates and styrenes selected from glycidyl methacrylate, 2-hydroxyethyl, methacryliate, hydroxypropyl methacrylate (all isomers), hydroxybutyl methacrylate (all isomers), N,N-dimethylaminoethyl methacrylate, N,N-diethylaminoethyl methacrylate, triethyleneglycol methacrylate, itaconic anhydride, itaconic acid, glycidyl acrylate, 2-hydroxyethyl acrylate, hydroxypropyl methacrylate (all isomers), hydroxybutyl acrylate (all isomers), N,N- dimethylaminoethyl acrylate, N,N-diethylaminoethyl acrylate, triethyleneglycol acrylate, methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide, N-terbtbutylmethacrylamide, N-n-butylmethacrylamide, N-methylolmethacrylamide, N-methylotmethacrylamide, N-tert-butylacrylamide. N-n-butylacrylamide, N-methylolacrylamide, N-ethylolacrylamide, vinyl benzoic acid (all isomers), dethylaminostyrene (all isomers), alpha-methylvinyl benzoic acid (all isomers), dethylamino alpha-methylstyrene (all isomers). p-vinylbenzene sulfonic acid, p-vinylbenzene sulfonic sodium salt, trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate, dimethoxymethylsilylpropyl methacrylate, dimethoxymethylsilylpropyl methacrylate, dibutoxymethylsilypropyl methacrylate, diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropyl methacrylate, diethoxysilylpropyl methacrylate, dibutoxy, silylpropyl methacrylate, diisopropoxysilylpropyl methacrylate, trimethoxysilyipropyl acrylate, triethoxysifylylpropyl acrylate, tributoxysilylpropyl acrylate, dimethoxymethylsilylpropyl acrylate, diethoxymethylsilylpropyl acrylate, dibutoxymethylsilylpropyl acrylate, diisopropoxymethylsilyipropyl acrylate, dimethoxysilylpropyl acrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate, diisopropoxysilylpropyl amiate, vinyl acetate, vinyl butyrate, vinyl benzoate, vinyl chloride, vinyl fluoride, vinyl bromide, maleic anhydride, N-phenylmaleimide, N-butylmaleimide, N-vinylpyrrolidone, N-vinylcarbazole, butadiene, isoprene, chloroprene, ethylene, and propylene, and combinations thereof.
Preferred monomers are C1-C8 acrylates , C1-C8 methacrylates, styrene, butadiene, isoprene and acrylonitrile.
As noted above, in order to initiate the free radical polymerization process, it is often desirable to utilize an initiator as a source for initiating free radicals. Generally, the source of initiating radicals can be any suitable method of generating free radicals such as the thermally induced homolytic scission of a suitable compound(s) (thermal initiators such as peroxides, peroxyesters, or azo compounds), the spontaneous generation from monomer (e.g., styrene), redox initiating systems, photochemical initiating systems or high energy radiation such as electron beam, X- or gamma-radiation. The initiating system is chosen such that under the reaction conditions there is no substantial adverse interaction of the initiator or the initiating radicals with the transfer agent under the conditions of the experiment. The initiator should also have the requisite solubility in the reaction medium or monomer mixture. The s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the invention can serve as an initiator, but the reaction must be run at a higher temperature.
Therefore, optionally it is desirable to utilize an initiator other than the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonates compounds of the present invention.
Thermal initiators are chosen to have an appropriate half-life at the temperature of polymerization. These initiators can include one or more of the following compounds:
2,2xe2x80x2-azobis(isobutyronitrile)(AIBN), 2,2xe2x80x2-azobis(2-cyano-2-butane), dimethyl 2,2xe2x80x2-azobisdimethylisobutyrate, 4,4xe2x80x2-azobis(4-cyanopentanoic acid), 1,1xe2x80x2-azobis(cyclohexanecarbanitrile), 2-(t-butylazo)-2-cyanopropane, 2,2xe2x80x2-azobis[2-methyl-N-(1,1)-bis(hydoxymethyl)-2-hydroxyethyl] propionamide, 2,2xe2x80x2-azobis[2-methyl-N-hydroxyethyl)]-propionamide, 2,2xe2x80x2-azobis(N,Nxe2x80x2-dimethyleneisobutyramidine) dihydrochloride, 2,2xe2x80x2-azobis(2-amidinopropane) dihydrochloride, 2,2xe2x80x2-azobis(N,Nxe2x80x2-dimethyleneisobutyramine), 2,2xe2x80x2-azobis(2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl] propionamide), 2,2xe2x80x2-azobis(2-methyl-N-[1,1-bis(hydroxymethyl) ethyl] propionamide), 2,2xe2x80x2-azobis[2-methyl-N-(2-hydroxyethyl) propionamide], 2,2xe2x80x2-azobis(isobutyramide) dehydrate, 2,2xe2x80x2-azobis(2,2,4-trimethylpentane), 2,2xe2x80x2-azobis(2-methylpropane), t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyoctoate, t-butylperoxyneodecanoate, t-butylperoxy isobutyrate, t-amyl peroxypivalate, t-butyl peroxypivalate, di-isopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, dicumyl peroxide, dibenzoyl peroxide, dilauroylperoxide, potassium peroxydisulfate, ammonium peroxydisulfate, di-t-butyl hyponitrite, dicumyl hyponitrite.
Photochemical initiator systems are chosen to have the requisite solubility in the reaction medium or monomer mixture and have an appropriate quantum yield for radical production under the conditions of the polymerization. Examples include benzoin derivatives, benzophenone, acyl phosphine oxides, and photo-redox systems production under the conditions of the polymerization; these initiating systems can include combinations of the following oxidants and reductants:
oxidants: potassium peroxydisuffate, hydrogen peroxide, t-butyl hydroperoxide reductants: iron (11), titanium (111), potassium thiosulfite, potassium bisulfite.
Other suitable initiating systems are described in recent texts. See, for example, Moad and Solomon xe2x80x9cThe Chemistry of Free Radical Polymerizationxe2x80x9d. Pergamon, London. 1995. pp 53-95.
The preferred initiators of the present invention are 2,2xe2x80x2-azobis(isobutyronitrile)(AIBN), or 4,4xe2x80x2-azobis(4-cyanopentanoic acid), or 2,2xe2x80x2-azobis(2-cyano-2-butane), or 1,1xe2x80x2-azobis(cyclohexanecarbanitrile). The amount of initiators utilized in the polymerization process can vary widely as generally from about 0.001 percent to about 99 percent, and desirably from about 0.01 percent to about 50 or 75 percent based on the total moles of chain transfer agent utilized. Preferably small amounts are utilized from about 0.1 percent to about 5, 10, 15, 20, or 25 mole percent based on the total moles of chain transfer agent utilized, i.e. said s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds. In order to form polymers which are, predominately telechelic, initiators other than the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds are utilized in lesser amounts, such as from about 0.001 percent to about 5 percent, desirably from about 0.01 percent to about 4.5 percent, and preferably from about 0.1 percent to about 3 percent based on the molar equivalent to the total moles of chain transfer agent utilized.
Optionally, as noted above, solvents may be utilized in the free radical polymerization process. Examples of such solvents include, but are not limited to, C6-C12 alkanes, toluene, chlorobenzene, acetone, t-butyl alcohol, and dimethylformamide. The solvents are chosen so that they do not chain transfer themselves. The amount of solvent utilized in the present invention polymerization process is generally from about 10 percent to about 500 percent the weight of the monomer, and preferably from about 50 percent to about 200 percent the weight of the monomer utilized in the polymerization.
As stated above, it is preferable to utilize the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the invention as chain transfer agents in the free radical polymerization process. The amount of chain transfer agent (CTA) utilized depends on the desired molecular weight of the polymer to be formed and can be calculated as known by one skilled in the art. A formula for calculating the amount of chain transfer agent is as follows:       Mn              xe2x80x83            of              xe2x80x83            polymer    =            (                        Weight                                xe2x80x83                              of                                xe2x80x83                              monomer          xc3x97          molecular                                xe2x80x83                              weight                                              xe2x80x83                                                  xe2x80x83                                          CTA                          Weight                                xe2x80x83                              of                                xe2x80x83                              CTA                    )        +          molecular                    xe2x80x83                  weight                    xe2x80x83                  of                              xe2x80x83                                  xe2x80x83                          CTA
While not wishing to be limited to any particular mechanism, it is believed that the mechanism of the free radical living polymerization process is as follows when using a vinyl monomer:
Alternatively, the reaction can proceed as follows:
As can be seen from the above mechanism, polymers having two different structures, see XIX and XXII, can be formed. The resulting polymers are either telechelic polymers (formed by the trithiocarbonate compounds of the present invention) with identical. functional groups at the ends of the chain, or a polymer having a single functional end group and also an initiator terminated chain (formed by using a conventional initiator such as AIBN). As stated above, the ratios between the resulting polymers can be controlled to give desired results and generally depends on the amount of initiator utilized. Obviously, if the initiator is the only s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound of the present invention, the resulting polymers are always telechelic. The greater the amount of the other initiator utilized, proportionally decreases the amount of telechelic polymers formed. Generally, the amount of the repeat group m, mxe2x80x2, mxe2x80x3, n, nxe2x80x2, or nxe2x80x3, is generally from about 1 to about 10,000, desirably from about 5 to about 500, and preferably from about 10 to about 200. Inasmuch as one or more vinyl monomers and/or one or more diene monomers can be utilized, it is to be understood that repeat groups of the polymers of the present invention are generally indicated by formulas XIX and XXII and can be the same or different. That is, random copolymers, terpolymers, etc., can be formed within either of the two repeat groups noted, as well as block cop olymers which can be formed. by initially adding one monomer and then subsequently adding a different monomer (e.g. an internal block copolymer).
The polymers formed by thexe2x80x2present invention can be generally represented by the following formula:
wherein such monomers are described herein above. Of course, the above formula can contain an initiator end group thereon as in XXII.
The reaction conditions are chosen as known to one skilled in the art so that the temperature utilized will generate a radical in a controlled fashion, wherein the temperature is generally from about room temperature to about 200xc2x0 C. The reaction can be run at temperatures lower than room temperature, but it is impractical to do so. The temperature often depends on the initiator chosen for the reaction, for example, when AIBN is utilized, the temperature generally is from about 40xc2x0 C. to about 80xc2x0 C., when azo dicyanodivaleric acid is utilized, the temperature generally is from about 50xc2x0 C. to about 90xc2x0 C., when di-t-butylperoxide is utilized, the temperature generally is from about 110xc2x0 C. to about 160xc2x0 C., when s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid) is utilized, the temperature is generally from about 80xc2x0 C. to about 200xc2x0 C.
The low polydispersity polymers prepared as stated above by the free radical polymerization can contain reactive end groups from the monomers which are able to undergo further chemical transformation or reaction such as being joined with another polymer chain, such as to form block copolymers for example. Therefore, any of the above listed monomers, i.e. conjugated dienes or vinyl containing monomers, can be utilized to form block copolymers utilizing the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds as chain transfer agent. Alternatively, the substituents may be non-reactive such as alkoxy, alkyl, or aryl. Reactive groups should be chosen such that there is no adverse reaction with the chain transfer agents under the conditions of the experiment.
The process of this invention can be carried out in emulsion, solution or suspension in either a batch, semi-batch, continuous, or feed mode. Otherwise-conventional procedures can be used to produce narrow polydispersity polymers. For lowest polydispersity polymers, the chain transfer agent is added before polymerization is commenced. For example, when carried out in batch mode in solution, the reactor is typically charged with chain transfer agent and monomer or medium plus monomer. The desired amount of initiator is then added to the mixture and the mixture is heated for a time which is dictated by the desired conversion and molecular weight. Polymers with broad, yet controlled, polydispersity or with multimodal molecular weight distribution can be produced by controlled addition of the chain transfer agent over the course of the polymerization process.
In the case of emulsion or suspension polymerization the medium will often be predominately water and the conventional stabilizers, dispersants and other additives can be present. For solution polymerization, the reaction medium can be chosen from a wide range of media to suit the monomer(s) being used.
As already stated, the use of feed polymerization conditions allows the use of chain transfer agents with lower transfer constants and allows the synthesis of block polymers that are not readily achieved using batch polymerization processes. If the polymerization is carried out as a feed system the reaction can be carried out as follows. The reactor is charged with the chosen medium, the chain transfer agent and optionally a portion of the monomer(s). The remaining monomer(s) is placed into a separate vessel. Initiator is dissolved or suspended in the reaction medium in another separate vessel. The medium in the reactor is heated and stirred while the monomer+medium and initiator+medium are introduced over time, for example by a syringe pump or other pumping device. The rate and duration of feed is determined largely by the quantity of solution the desired monomer/chain transfer agent/initiator ratio and the rate of the polymerization. When the feed is complete, heating can be continued for an additional period.
Following completion of the polymerization, the polymer can be isolated by stripping off the medium and unreacted monomer(s) or by precipitation with a non-solvent. Alternatively, the polymer solution/emulsion can be used as such, if appropriate to its application.
The invention has wide applicability in the field of free radical polymerization and can be used to produce polymers and compositions for coatings, including clear coats and base coat finishes for paints for automobiles and other vehicles or maintenance finished for a wide variety of substrates. Such coatings can further include pigments, durability agents, corrosion and oxidation inhibitors, rheology control agents, metallic flakes and other additives. Block and star, and branched polymers can be used as compatibilisers, thermoplastic elastomers, dispersing agents or rheology control agents. Additional applications for polymers of the invention are in the fields of imaging, electronics (e.g., photoresists), engineering plastics, adhesives, sealants, and polymers in general.
As can be seen in the above shown polymerization mechanism, the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound can be utilized to create telechelic polymers having two functional groups at both chain ends.
The term xe2x80x9ctelechelic polymerxe2x80x9d was proposed in 1960 by Uraneck et al. to designate relatively low molecular weight macromolecules possessing one or more, and preferably two reactive functional groups, situated at the chain ends, thereof. The functional end groups of both the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound and the polymers formed therefrom, have the capacity for selective reaction to form bonds with another molecule. The functionality of a telechelic polymer or prepolymer is equal to the number of such end groups. Telechelic polymers containing a functional group, such as COOH, at each end are useful for synthesizing further chain extended copolymers and block copolymers.
The interest in telechelic polymers resides in the fact that such polymers can be used, generally together with suitable linking agents, to carry out three important operations: (1) chain extension of short chains to long ones by means of bifunctional linking agents, (2) formation of networks by use of multifunctional linking agents, and (3) formation of (poly)block copolymers by combination of telechelics with different backbones. These concepts are of great industrial importance since they form the basis of the so-called xe2x80x9cliquid polymerxe2x80x9d technology exemplified by the xe2x80x9creaction injection moldingxe2x80x9d (RIM). Great interest has also been shown by the rubber industry because the formation of a rubber is based on network formation. In classical rubber technology, this is achieved by the cross-linking of long chains that show high viscosity. The classical rubber technology, therefore, requires an energy-intensive mixing operation. The use of liquid precursors, which can be end-linked to the desired network, offers not only processing advantages, but in some cases, also better properties of the end-product. Further information about telechelic polymers and synthesis thereof can be found in xe2x80x9cTelechelic Polymers: Synthesis and Applicationsxe2x80x9d by Eric J. Goethe, CRC Press, Boca Raton, Fla., 1989.
The reaction conditions for the reactive functional acid end groups of the telechelic polymers or s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention are generally the same as those for forming the above noted free radical polymers. The acid in the monomeric or in the polymeric form can be transformed to its derivatives in the conventional manner. For example, the ester can be made by refluxing the acid in alcohol with an acid catalyst with removal of water. Amides can be formed by heating the acid with an amine with the removal of water. 2-hydroxy-ethyl ester can be formed by directly reacting the acid with an epoxide with or without a catalyst such as triphenylphosphine or an acid like toluene-sulfonic acid. As seen by the examples below, any of the above noted monomers such as the one or more diene monomers or one or more vinyl containing monomers, can be utilized to form the telechelic monomers from the bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the present invention. Any of the above noted components, such as solvent, etc., can be utilized in the herein above stated amounts.
The acid groups of the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound can be converted to other functional groups either before or after polymerization. Even if the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds have functional end groups which have been converted from the acid end groups before polymerization, the monomers added during polymerization still add to the chain between the sulfur-tertiary carbon as shown in the mechanisms above as well as below at XXIII and XXIV. The carboxylic end groups of the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds or the polymerized s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds can be converted or changed into other functional end groups such as esters, thioesters, amides, beta mercapto esters, beta hydroxy esters, or beta amino esters. Examples of these functional end groups are shown below.
An example reaction forming a telechelic polymer from the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds of the invention when using a vinyl monomer is as follows:
Of course, it is to be understood as indicated above, that the repeat units m and n can be derived either from conjugated diene monomers, or the indicated vinyl monomers, or combinations thereof, as generally set forth in formula W.
Subsequently, other functional end groups can be derived from the acid groups of the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compound and can generally be represented by the formula:
where E is set forth below. For example,
wherein E is XRxe2x80x2, that is Rxe2x80x2, independently, comprises H, C1-C18 alkyls which can be optionally substituted with one or more halogen, hydroxyl, or alkoxy, C1-C18 hydroxyalkyls, and C1-C18 aminoalkyls and X comprises oxygen, sulfur, NH, or NRxe2x80x2.
The following is still another example of functional end groups which can be derived from the acid:
wherein E is
that is where R6 through R9, independently comprise H, C1-C18 alkyls, aryl groups or substituted aryl groups having from 1 to 6 substituents on the ring, such as halogen, hydroxyl, or alkoxy, C1-C18 hydroxyalkys, C1-C18 aminoalkyls, C1-C18 mercapto alkyls, and the like. Y can comprise oxygen, sulfur, NH, or NR6 to R9.
A further example of still other functional end groups which can be derived from the acid groups of the s,sxe2x80x2-bis-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate compounds is as follows:
wherein E is OR10, that is where Z can comprise a leaving group, such as a halide or alkylsulfonate or aryl sulfonate. R10 can comprise C1-C18, a alkyl or substituted alkyl wherein said substituent is halogen, hydroxyl, or alkoxy, C1-C18 hydroxyalkyl or C1-C18 amino alkyl and the like.
Preparation of the above shown methylesters of s,sxe2x80x2-bis-(2-methyl-2-propanoic acid)-trithiocarbonate is as follows: s,sxe2x80x2-bis-(2-methyl-2-propanoic acid) trithiocarbonate (R1,R2xe2x95x90CH3) (2.82 g, 0.01 mole), Sodium carbonate powders (3.18 g, 0.03 mole) and 15 ml dimethyl formamide were stirred under nitrogen at 40xc2x0 C. while a solution of methyliodide (3.41 g, 0.024 mole) in 2 ml dimethylformamide was added dropwise over 10 minutes. The reaction Was stirred at 40-50xc2x0 C. for 2 hours, poured into 25 ml H2O and extracted 3 times with a total of 200 ml. ether. The etherate solution was dried over magnesium sulfate and concentrated. The yellow solid was further purified by recrystallization from hexanes. Infrared and Hxe2x80x2NMR showed the above desired product.
An example of an already formed telechelic polymer, made from a vinyl monomer, undergoing conversion of the acid end group is as follows:
where m and n are as set forth above.
The above structure (XXXIV) was formed by reaction of epoxide with s,sxe2x80x2-bis-(2-methyl-2-propanoic acid)-trithiocarbonate (I)(R1,R2xe2x95x90CH3, 0.01 mole) of the present invention and Epon(copyright) Resin 828 (Shell chemicals, reaction product of bisphenol A and epichlorohydrin, 80-85% diglycidyl ethers of bisphenol A) (70 g) and trephenyl phosphine (0.12 g) were heated to 95xc2x0 C. under nitrogen. The reaction was monitored for the disappearance of the carboxylic acid by titration. It was found the reaction was essentially complete in 1.5 hours. The product structure can be further confirmed by mass spectroscopy.
Another aspect of present invention further relates to forming the following compounds:
wherein R11 comprises a benzyl group, C1-C18 alkyl, or substituted alkyl such as halogen, hydroxyl, or alkoxy, C1-C18 hydroxyalkyl, carboxylalkyl, or carboalkoxyalkyl. Q+Xxe2x88x92 is a phase transfer catalyst such as tetrabutylammoniumhydrogensulfate, or octadecyltrimethylammoniumchloride (Aliquot 336).
The resulting compound is an s-substituted alkyl-sxe2x80x2-(xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate. R11 is an alkyl having from 1-18 carbon atoms, aralkyl, hydroxyalkyl, cyanoalkyl, aminoalkyl, carboxylalkyl, or carboalkoxyalkyl, mercaptoalkyl, etc. R1 and R2 are as stated herein above.
When s-substituted alkyl -sxe2x80x2- (xcex1,xcex1xe2x80x2-disubstituted-xcex1xe2x80x3-acetic acid)-trithiocarbonate is employed either as an inifertor, or as a chain-transfer agent, unless R11 is carboxyl alkyl, only one end of the polymer has a carboxyl function, i.e. it is no longer a telechelic polymer.
While various polymers have been set forth herein above, it is to be understood that any of the carboxyl terminated polymers, such as W, or the E terminated polymers, and the like, can be reacted with one or more monomers and/or one or more polymers know to the art and to the literature to yield various resulting block polymers which are derived from the same monomer or from two or more different monomers. For example, each acid end group can be reacted with an excess of an epoxy compound such as a glycidyl bisphenol A and then subsequently polymerized with additional glycidyl bisphenol A to form an epoxy polymer. Naturally, other block polymers or copolymers can be reacted with the carboxylic end group or the other end groups generally denoted by E herein above.

S,Sxe2x80x2BIS-(xcex1, xcex1xe2x80x2-DISUBSTITUTED-xcex1xe2x80x3-ACETIC ACID)- TRITHIOCARBONATES AND DERIVATIVES AS INITIATOR-CHAIN TRANSFER AGENT-TERMINATOR FOR CONTROLLED RADICAL POLYMERIZATIONS AND THE PROCESS FOR MAKING THE SAME