Direct copolymerization of L-lactic acid with γ-butyrolactone in the absence of catalysts
Direct copolymerization of L-lactic acid with γ-butyrolactone in the absence of catalysts
复制标题
L-乳酸与γ-丁内酯无催化剂直接共聚
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
M. Kumakura
中科院分区：
文献类型：
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作者：
H. Fukuzaki;Yoshikazu Aiba;Masaru Yoshida;M. Asano;M. Kumakura
L-乳酸（LA）与γ-丁内酯（BL）的共聚合在没有催化剂的情况下在200°C下在氮气下进行以获得相对低分子量的共聚物，通过直链LA与通过环状BL的水解产生的直链4-羟基丁酸之间的直接缩合进行。共聚物的共聚性（13 C NMR光谱），组成（1H NMR光谱），分子量（端基分析和凝胶渗透色谱法），和结晶度（差示扫描量热法）进行了表征。BL的共聚能力较低，e.例如，在一个实施例中，当单体进料中的初始BL含量为30、50和70 mol- %时，共聚物中BL单元的含量分别为12、16和19 mol- %，其中共聚（LA/BL）由单个γ-氧丁酰基单元分隔的乳酰基单元的嵌段组成。
The copolymerization of L-lactic acid (LA) with γ-butyrolactone (BL), performed without catalyst at 200°C under nitrogen in order to obtain a relatively low-molecular-weight copolymer, proceeds via direct condensation between linear LA and linear 4-hydroxybutyric acid produced by hydrolysis of the cyclic BL. The copolymers were characterized with respect to the copolymerizability (13C NMR spectroscopy), composition (1H NMR spectroscopy), molecular weight (terminal group analysis and gel permeation chromatography), and crystallinity (differential scanning calorimetry). The copolymerizability of BL is low, e. g., the contents of BL units in the copolymers were found to be 12, 16, and 19 mol-% for initial BL contents in the monomer feed of 30, 50, and 70 mol-%, respectively, in which copoly(LA/BL) is composed of blocks of lactyl units separated by single γ-oxybutyryl unit.