Hydrolytic Degradation of Aliphatic Polyesters Copolymerized with Poly(ethylene glycol)s

✍ Scribed by Nagata, Minoru; Kiyotsukuri, Tsuyoshi; Takeuchi, Shigeki; Tsutsumi, Naoto; Sakai, Wataru

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 276 KB
• Volume: 42
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(199701)42:1<33::aid-pi655>3.0.co;2-9

✦ Synopsis

Poly(1,4-butanediol succinate) copolymers were prepared by melt polycondensation of succinic acid and 1,4-butanediol with 10È50 mol% (in feed) of poly(ethylene glycol) (PEG), where molecular weight (MW) of PEG is 200È 2000. The reduced speciÐc viscosity of the copolymers increased with incorporation of the PEG component, but a higher PEG content in the copolymers reduced it. The temperature of melting and crystallinity decreased with (T m ) increasing PEG content. depression of the copolymers followed approx-T m imately FloryÏs equation, suggesting that these are random type copolymers. Tensile strength and elongation decreased with increasing MW and content of PEG. The weight loss of copolymer Ðlms in a bu †er solution with or without lipase at 37¡C, as well as water absorption, increased with increasing PEG content, implying that higher water absorption contributes to hydrolytic degradation of the Ðlms. However, the weight loss of copolymers with PEG of lower MW increased greatly in spite of lower water absorption, demonstrating that hydrolytic degradation is inÑuenced by the concentration of degradable ester linkages between succinic acid and PEG segments rather than water absorption.