作　　者： ; ; ; ; ;

机构地区： 仲恺农业工程学院化学化工学院

出　　处： 《中国塑料》 2011年第1期60-64,共5页

摘　　要： 采用NaBr、NaCl、NaI、KI、KCl与KBr作为D,L-乳酸直接缩聚合成聚乳酸(PLA)的催化剂,比较了各种催化剂的催化效果。研究了催化剂浓度、反应时间、反应温度对聚合反应的影响。通过红外光谱、核磁共振、凝胶渗透色谱、差示扫描量热及热重分析等测试方法对PLA的结构和性能进行了表征。结果表明,KI的催化效果最佳;当催化剂KI用量为单体用量的0.2倍(物质的量比),反应时间为12 h,聚合温度为130℃时,PLA的重均相对分子质量为1.151×105,产率为70.73%。PLA的相对分子质量越大,玻璃化转变温度(Tg)越高。PLA的热分解温度随催化剂用量的增加而下降。 The direct polycondensation method with different catalysts was used to synthesize poly （lactic acid）（PLA）from D, L lactic acid, the catalytic effect of NaBr, NaCl, NaI, KI, KCl and KBr was compared. The influences of dosage of catalysts, reaction time and reaction temperature on the polymerization were discussed. The PLA was characterized using infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry and thermogravimetry. It showed that KI was the optimum catalyst. When the molar ratio of KI to D, L-lactic acid was 0. 2,polymerization t/me was 12 h, reaction temperature was 130 ℃, the weight-average molecular weight of the obtained PleA was 1. 151 × 10^5 with a yield of 70. 73 %. With increasing relative molecular mass of PLA, the glass transition temperature increased. The thermal decomposition temperature of PLA decreased with increasing dosage of catalysts.

关 键 词： 聚乳酸 碘化钾 缩聚 催化剂浓度 反应时间 反应温度 重均相对分子质量

领　　域： [化学工程]