POLY 670 |
| Enzyme-catalyzed synthesis and degradation of a typical diol-diacid type plastic, poly(butylene succinate) (PBS), and diol-diacid type polythioester were studied with respect to the establishment of sustainable polymer production and chemical recycling system. A significantly higher-molecular-weight polyester was produced via the ring-opening polymerization of the cyclic oligomer. The cyclic oligomer was produced both by the condensation of monomers and degradation of the polyester. Polymer blends of PBS/poly(L-lactic acid) (PLLA) were degraded into repolymerizable oligomers, first by the lipase-catalyzed degradation of PBS into cyclic BS oligomers followed by the degradation of PLLA into lactic acid oligomers by montmorillonite K-5. By the reprecipitation procedures, the PLLA and BS oligomers were completely separated. Aliphatic dithiol-diacid type polythioesters were enzymatically prepared by the direct polycondensation of dithiol and diacid diesters. A higher molecular weight polythioester was produced using lipase in a two-step procedure, i.e., cyclization with subsequent ring-opening polymerization. |
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Biocatalysis in Polymer Science
8:30 AM-11:45 AM, Thursday, 14 September 2006 San Francisco Marriott -- Salon 12/13, Oral
Division of Polymer Chemistry |