【摘要】 以乳酸为原料,常压下运用溶液直接缩聚法合成了具有一定粘均分子量的聚乳酸。实验过程中考察了不同带水剂、催化剂对聚乳酸分子量的影响以及反应时间与分子量的变化关系。结果表明,本实验条件下合成聚乳酸的最佳工艺条件为:选择氯化亚锡为催化剂,用量0.5wt%,在聚合温度120℃、常压下反应20h。在此条件下,可获得较高分子量的聚乳酸。这也为探究如何生成分子量较高的聚乳酸提供一定的参考依据。更多还原

【Abstract】 Lactic acid as raw material was used in this experiment and liquor-direct polycondensation was mainly used to synthesize PLA with a certain viscosity-average molecular weight.In this experiment,the influence of different water-taking agent,catalyst on PLA’s molecular weight and the relation between reaction time and molecular weight were observed.The result demonstrated the best technics condition of synthesizing PLA.Under the standard pressure,0.5wt% of SnCl₂ was used as catalyst.Polycondensation temperature was controlled at 120℃ and the reaction time was 20h.Under this condition,PLA with larger molecular weight could be synthesized.This experiment and conclusion also provided reference to the investigation of how to produce the PLA with larger molecular weight.更多还原