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论文类型：期刊论文

发表时间：2007-04-01

发表刊物：EUROPEAN POLYMER JOURNAL

收录刊物：SCIE、EI

卷号：43

期号：4

页面范围：1210-1218

ISSN号：0014-3057

关键字：beta-butyrolactone; poly-3-hydroxybutyrate; dibutylmagnesium; kinetics; mechanism

摘要：Ring opening polymerization (ROP) of (R,S)-beta-butyrolactone (BL) using dibutylmagnesium (Bu2Mg) as initiator was investigated both in bulk and in solution. The synthetic poly-3-hydroxybutyrates (P3HB) were characterized by H-1 NMR, C-13 NMR, FT-IR and GPC. Effects of molar ratio of initiator to monomer, reaction temperature and time on the monomer conversion and the polymer molecular weight and its distribution were discussed. The kinetics of the solution polymerization of BL was examined and showed a first order both in monomer concentration and initiator concentration. The end groups analysis suggested that the monomer inserted into the growing chain proceeding through the coordination-insertion mechanism based on the acyl-oxygen bond scission rather than the alkyl-oxygen bond cleavage of the BL ring. Furthermore, a possible mechanism for the initiation and propagation procedures of P3HB synthesized from BL with Bu2Mg was proposed. (C) 2007 Elsevier Ltd. All rights reserved.