POLYLACTONES .1. COPOLYMERIZATION OF GLYCOLIDE AND EPSILON-CAPROLACTONE
POLYLACTONES .1. COPOLYMERIZATION OF GLYCOLIDE AND EPSILON-CAPROLACTONE
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DOI：
10.1021/ma00140a051
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发表时间：
1984-01-01
期刊：
影响因子：
5.5
通讯作者：
JONTE, JM
中科院分区：
文献类型：
--
作者：
KRICHELDORF, HR;MANG, T;JONTE, JM
乙交酯和ε-己内酯的共聚在100°C下，在硝基苯或二恶烷中，在70,100或150°C下进行。所得共聚酯通过NMR谱表征其摩尔组成，并通过13C NMR谱表征其序列。结果允许对共聚酯和引发剂进行分类。阳离子引发剂如氯化铁、三氟化硼和氟磺酸有利于ε-己内酯的掺入，催化分子间酯交换反应，并导致聚酯在100℃以上快速降解。络合催化剂如氯化锌、异丙醇铝和二甲基二丁基锡有利于乙交酯的掺入和一级化学异质性。此外，在异丙醇铝和二甲基二丁基锡的情况下检测到分子内酯交换反应。阴离子催化剂如苯甲酸四甲基铵和氯化苄基三苯基鏻仅引发乙交酯的均聚。讨论了聚合机理。差示扫描量热法显示了结晶度和序列性质之间的密切关系。
Copolymerization of glycolideand e-caprolactone was conducted in bulk at 100 C and in nitrobenzene or dioxane at 70,100, or 150 C. The resulting copolyesters were characterized with respect to their molar composition by means of NMR spectra and with respect to their sequences by means of 13C NMR spectra. The results allow a classification of both copolyesters and initiators. Cationic initiators such as ferric chloride, boron trifluoride, and fluorosulfonic acid favor the incorporationof e-caprolactone, catalyze intermolecular transesterifications, and cause rapid degradation of the polyesters above 100 C. Complexing catalysts such as zinc chloride, aluminum isopropylate, and dibutyltin dimethylate favor the incorporation of glycolide and chemical heterogeneity of first order. Furthermore, intramolecular transesterification was detected in the case of aluminum isopropylateand dibutyltin dimethylate. Anionic catalysts such as tetramethylammonium benzoate and benzyltriphenylphosphonium chloride only initiate the homopolymerization of glycolide. The polymerization mechanisms are discussed. The differential scanning calorimetry shows a close relationship between crystallinity and nature of sequences.