Degradation of poly(D,L‐lactic acid)‐b‐poly(ethylene glycol) copolymer and poly(L‐lactic acid) by electron beam irradiation |
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| Authors: | Peikai Miao Dimeng Wu Ke Zeng Chun'e Zhao Guoliang Xu Zhifu Huang Gang Yang |
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| Affiliation: | 1. College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Application and Research Center for Electron Beams of College of Polymer‐NHVC, Sichuan University, Chengdu 610065, People's Republic of China;2. Technical R&D Department, R&D Center, Hunan Sokan New Materials Co., Ltd., Ningxiang 410600, People's Republic of China |
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| Abstract: | This article investigated the effects of electron beam (EB) irradiation on poly(D ,L ‐lactic acid)‐b‐poly(ethylene glycol) copolymer (PLEG) and poly(L ‐lactic acid) (PLLA). The dominant effect of EB irradiation on both PLEG and PLLA was chain scission. With increasing dose, recombination reactions or partial crosslinking of PLEG can occur in addition to chain scission, but there was no obvious crosslinking for PLLA at doses below 200 kGy. The chain scission degree of irradiated PLEG and PLLA was calculated to be 0.213 and 0.403, respectively. The linear relationships were also established between the decrease in molecular weight with increasing dose. Elongation at break of the irradiated PLEG and PLLA decreased significantly, whereas the tensile strength and glass transition temperature of PLLA decreased much more significantly compared with PLEG. The presence of poly(ethylene glycol) (PEG) chain segment in PLEG was the key factor in its greater stability to EB irradiation compared with PLLA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 |
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| Keywords: | biopolymer crosslinking degradation electron beam irradiation molecular structure |
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