Researchers at the Fraunhofer Institute for Applied Polymer Research IAP have managed to embed enzymes in plastics without the enzymes losing their activity in the process. The potentials this creates are enormous.
Materials that clean themselves, have anti-mold surfaces or are even self-degrading are just a few examples of what will be possible if we manage to embed active enzymes into plastics. But for the enzyme-specific properties to be transferred to the materials, the enzymes must not suffer damage as they are embedded in the plastic. Scientists at Fraunhofer IAP have developed a solution to the problem as part of the “Biofunctionalization/Biologization of Polymer Materials BioPol” project. Since summer 2018, the project has been running in cooperation with BTU Cottbus-Senftenberg.
The research aims to produce biofunctionalized plastics on a production scale. Enzymes have been successfully embedded, both in terms of the enzymes themselves and the processing technique.
Plastics are processed at way over a hundred degrees Celsius. Enzymes, by contrast, cannot usually withstand these high temperatures. Seeking a way to stabilize the enzymes, the researchers use inorganic carriers. These carriers act as a kind of protection for the enzyme. As Dr. Ruben R. Rosencrantz, Head of the “Biofunctionalized Materials and (Glyco)Biotechnology” department at Fraunhofer IAP, explains: “We use inorganic particles, for example, which are highly porous. The enzymes bind to these carriers by embedding in the pores. Although this restricts the enzymes’ mobility, they remain active and are able to withstand much higher temperatures.”
Stabilized enzymes: not only at the plastic surface, but inside too: The researchers deliberately sought a way of applying the stabilized enzymes not only to the surface of the plastic, but of embedding them into the plastics directly. “Although far more difficult, this technique also prevents signs of wear on the material surface affecting the functionality of the plastics,” explains Thomas Büsse who heads the institute’s processing pilot plant for biopolymers in Schwarzheide.
In order to achieve an optimum material result in the downstream process, the stabilized enzymes have to be distributed as quickly as possible in the hot plastic melt to which they are added, without becoming exposed to excess force or elevated temperatures. A balancing act that tipped in Büsse’s favor: “We have developed a process that is suitable for both bioplastics and for the conventional petroleum-based plastics such as polyethylene. Our investigations also show that once embedded in the plastic, stabilized enzymes are able to withstand higher thermal loads than before. This makes the use of enzymes and all process steps considerably easier.”
Self-cleaning plastics are just the beginning : Until now, the researchers at Fraunhofer IAP have evaluated mainly proteases as their choice of enzyme. Proteases are able to break up other proteins. This lends the plastic functionalized by these proteases a self-cleaning effect. Pipes, for example, would not close up or clog as readily. But other enzymes are being systematically tested as well. The cooperation partners at BTU Cottbus-Senftenberg are focusing more closely at enzymes for degrading plastics and toxic substances, for example.
The first functionalized plastic granulates, films and injection molding bodies have already been produced. The researchers have established that the enzymes embedded in these products remain active. The next step now is to test and further optimize the process for everyday use in various applications.
Source: Fraunhofer Institute for Applied Polymer Researc
Watafiti wa Taasisi ya Fraunhofer ya Utafiti wa Polymer ya Matumizi (FAP) wamefanikiwa kuingiza enzymes katika plastiki bila enzymes kupoteza shughuli zao katika mchakato huo. Uwezekano unaotokezwa na jambo hilo ni mkubwa sana. Vifaa vinavyojisafisha, vina uso wa kupambana na kuvu au vinavyojiharibu wenyewe ni mifano michache tu ya kile kinachowezekana ikiwa tutaweza kuingiza enzymes hai kwenye plastiki. Lakini kwa ajili ya mali maalum ya enzyme kuhamishwa kwa vifaa, enzymes lazima si kuteseka uharibifu kama wao ni embedded katika plastiki. Wanasayansi wa Fraunhofer IAP wametengeneza suluhisho la tatizo hilo kama sehemu ya mradi wa "Biofunctionalization/Biologization of Polymer Materials BioPol". Tangu mwaka 2018, kampuni hiyo imekuwa ikifanya kazi na kampuni ya BTU Cottbus-Senftenberg. Utafiti huo unakusudia kutengeneza plastiki za biofunctionalized kwa kiwango cha uzalishaji. Enzymes zimeingizwa kwa mafanikio, wote katika suala la enzymes wenyewe na mbinu ya usindikaji. Plastiki hutengenezwa kwa joto la zaidi ya nyuzi mia moja. Kwa kutofautisha, kwa kawaida vimeng'enya haviwezi kuvumilia halijoto hizo za juu. Wakitafuta njia ya kudumisha enzymes, watafiti hutumia vyombo vya usafirishaji visivyo vya kikaboni. Vifaa hivyo huhifadhi enzi hiyo. Ruben Rosencrantz, mkuu wa idara ya vifaa vya biofunctionalized na (Glyco) biotechnology katika Fraunhofer IAP, anaelezea: "Tunatumia chembechembe zisizo za kikaboni, kwa mfano, ambazo ni porous sana. Enzyme huunganishwa na vyombo hivyo kwa kuingizwa katika pores. Ingawa hii hupunguza mwendo wa enzymes, bado zinafanya kazi na zinaweza kuvumilia joto la juu zaidi.  Enzymes zilizowekwa: sio tu kwenye uso wa plastiki, lakini ndani pia: Watafiti walitafuta njia ya kutumia enzymes zilizowekwa sio tu kwenye uso wa plastiki, lakini kuziingiza moja kwa moja kwenye plastiki. "Hata ingawa ni ngumu zaidi, mbinu hii pia inazuia ishara za kuvaa kwenye uso wa nyenzo zinazoathiri utendaji wa plastiki", anaelezea Thomas Büsse ambaye anaongoza kiwanda cha majaribio cha taasisi ya usindikaji wa biopolymers huko Schwarzheide. Ili kufikia matokeo bora ya nyenzo katika mchakato wa chini, enzymes imara lazima kusambazwa haraka iwezekanavyo katika plastiki moto iliyoyeyushwa ambayo imeongezwa, bila kuathiriwa na nguvu ya ziada au joto la juu. Hatua ya kusawazisha ambayo ilibadilika kwa niaba ya Büsse: <unk>Tumeendeleza mchakato ambao unafaa kwa bioplastics na kwa plastiki za kawaida za mafuta kama vile polyethylene. Uchunguzi wetu pia unaonyesha kwamba mara moja iliyoingizwa katika plastiki, enzymes imara ni uwezo wa kuvumilia mzigo wa joto ya juu kuliko hapo awali. "Hii inafanya matumizi ya enzymes na hatua zote za mchakato rahisi sana. ""Plastiki za kujificha ni mwanzo tu: Hadi sasa, watafiti wa Fraunhofer IAP wamehesabu hasa proteases kama chaguo lao la enzyme." Proteasi zinaweza kuvunja protini nyingine. Hii inatoa plastiki functionalized na proteases hizi athari ya kujisafisha. Kwa mfano, mabomba hayangefungwa au kufungwa kwa urahisi. Lakini vimeng'enya vingine vinajaribiwa kwa utaratibu pia. Kampuni ya BTU Cottbus-Senftenberg imetoa utafiti wa kipekee kuhusu kemikali zinazohusika katika kuharibu plastiki na kemikali zenye sumu. Granulates ya kwanza ya plastiki, filamu na miili ya kuingiza tayari imetengenezwa. Watafiti wamegundua kwamba vimeng'enya vilivyo katika bidhaa hizo hubaki vikiwa hai. Hatua inayofuata sasa ni kupima na kuboresha mchakato kwa ajili ya matumizi ya kila siku katika maombi mbalimbali. Chanzo: Fraunhofer Taasisi ya Applied Polymer Research