【摘要】 以L-乳酸为原料,熔融缩聚法直接合成聚L-乳酸。考察了预聚工艺、催化剂配比及用量、反应温度、反应时间及真空度等条件对乳酸聚合反应的影响。通过红外光谱(FTIR)和核磁共振波谱(1H-NMR)分析和表征聚乳酸的结构,凝胶渗透色谱(GPC)测试其分子量及分子量分布。研究表明,较为适宜的工艺条件为:以二水合氯化亚锡(SnCl2.2H2O)和对甲基苯磺酸(TSA)为催化剂,且SnCl2.2H2O相对于乳酸预聚体的质量比为0.5%,真空度-0.98MPa,温度180℃,反应时间10h。得到的聚L-乳酸的粘均分子量为6.17×104,分子量分布1.37,且产率较高,色泽较浅。更多还原

【Abstract】 The melt polycondensation of L-lactic acid was studied.The effects of oligomerization conditions,catalyst,temperature,time,and system vaccum were discussed.The structure of PLLA was analyzed by FTIR and 1H NMR,and the molecular weight was tested by GPC.The study indicated that,with SnCl2·2H2O and TSA as the catalyst,the comparatively appropriate reaction conditions were as follows: the catalyst content was 0.5% to OLLA,polymerized at 180℃ for 10h under a system vacuum of-0.98MPa.As a result,the viscosity average molecular weight was 6.17×104,with a narrow molecular-weight distribution,high production rate and light color.更多还原