摘要
文章采用直接缩聚法合成端羧基乳酸预聚物,以1,6-己二醇二缩水甘油醚型环氧对其进行扩链,研究了2-甲基咪唑、苄基三乙基氯化铵、乙酸锌和乙酰丙酮锌对扩链反应的催化作用。采用差示扫描量热仪(DSC)跟踪反应过程,利用Kissinger公式和Crane公式分别计算扩链反应的表观活化能与表观反应级数。结果表明,4种催化剂作用下,环氧扩链端羧基聚乳酸反应的表观活化能分别为61.4、75.2、119.6、90.3 kJ/mol,采用2-甲基咪唑时,扩链反应的表观活化能最低,扩链反应近似为一级反应。
The carboxyl terminated lactic acid prepolymer was synthesized through melt polycondensation of L-lactic acid,and the chain extension reaction of the prepolymer was carried out by using 1,6-hexanediol diglycidyl ether as chain extender in the presence of one of the catalysts including 2-methylimidazole,benzyltriethylammonium chloride,zinc acetate and zinc acetylacetonate.The process of chain extension reaction was tracked by differential scanning calorimetry（DSC）.Subsequently,the apparent activation energy and reaction order were calculated by means of Kissinger and Crane methods.The results showed that the apparent activation energy values of chain extension reaction in the presence of 2-methylimidazole,benzyltriethylammonium chloride,zinc acetate or zinc acetylacetonate were 61.4 kJ/mol,75.2 kJ/mol,119.6 kJ/mol and 90.3 kJ/mol in turn.With the lowest apparent activation energy,2-methylimidazole was decided as the optimal catalyst.The chain extension was a first order reaction.
出处
《合肥工业大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第7期1076-1078,1095,共4页
Journal of Hefei University of Technology：Natural Science
基金
安徽省教育厅自然科学研究资助项目(09-840Z)
关键词
聚乳酸
扩链
催化反应
polylactic acid
chain extension
catalytic reaction
