Synthesis and biodegradation of copolyesterether of copoly(succinic anhydride/ethylene oxide) with triblock copolymer of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene)

✍ Scribed by Y. Maeda; A. Nakayama; I. Arvanitoyannis; N. Kawasaki; K. Hayashi; S. Aiba; N. Yamamoto

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 190 KB
• Volume: 69
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980711)69:2<303::aid-app11>3.0.co;2-x

✦ Synopsis

The thermal properties and biodegradability of the block copolyesterethers with copoly[succinic anhydride (SA)/ethylene oxide (EO)], synthesized by ring-opening copolymerization as a hard segment and the triblock copolyethers of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) (PN) as a soft segment, were studied. The block copolyesterethers synthesized from higher than 8000 number-average molecular weight (M n ) of copoly(SA/EO)s showed a microphase separation structure as determined by the thermal properties [melting point (T m ) and glass transition (T g )], at any polymer composition [EO/propylene oxide (PO)] or the determination of M n of PN. A decrease in the M n of copoly(SA/EO) or an increase in PO content in PN resulted in depression of heats of fusion ( DH) of these block copolyesterethers. The enzymatic degradation of the block copolyesterethers by the lipase from Rhizopus arrhizus showed a substantial increase with a decrease in their DH, whereas it was depressed with an increase in the M n of polyoxyethylene or polyoxypropylene segment in the block copolyesterethers. The block copolyesterethers were degraded by microorganisms in activated sludge. The biodegradability of the block copolyesterethers showed a pronounced drop, with an increase in the polyoxyethylene chain length or polyoxypropylene content in PN. The polycondensation was also conducted without a catalyst at 190ЊC, similarly, to the reaction catalyzed with Ti[OCH(CH 3 ) 2 ] 4 at 170ЊC. The effect of the residual titanium on the biodegradability of the block copolyesterethers was negligible.