摘要
以有机钛酸酯(Ti(OBu)4)为催化剂,考察了反应物碳酸二乙酯(DEC)和1,4-丁二醇(BDO)摩尔比、减压时间及温度、精馏柱塔板数等对酯交换反应的影响,制备出了相对分子质量在2000左右的聚碳酸酯二元醇(PCDL)。采用IR和1H-NMR表征了产物PCDL的分子结构,气相色谱法分析了馏分的组成。结果表明,常压阶段馏分为乙醇,与反应物的摩尔比无关;减压阶段,当反应物摩尔比>1.0时,DEC与乙醇形成共沸物一起被蒸出。当反应物摩尔比≥1.0时,所得产物的相对分子质量能够稳定地控制在2000左右。随着减压反应时间的延长和温度的升高,PCDL的相对分子质量逐渐增大,羟值则逐渐降低。
Polycarbonate diols （PCDL） which relative molecular mass was 2000 was synthesized using 1,4-butanediol （BDO） and diethyl carbonate （DEC） in the catalysis of titanate （Ti （OBu） 4 ）. The influences of molar ratio of DEC/BDO, vacuum reaction time and temperature and plate number were investigated. The structure of PCDL was determined by FT-IR and 1H-NMR, and the composition of fraction was determined by GC. The experimental results showed that the fraction of standard atmosphere stage was ethanol, and it had no influence on the molar ratio of DEC/BDO; DEC formed azeotrope with ethanol and was steamed together when molar ratio of DEC/BDO was more then 1.0. The molecular weight of PCDL could be stable on 2000 when molar ratio of DEC/BDO was greater than or equal to 1.0. The molecular weight of PCDL creasing. Meanwhile, the hydroxyl value decreased. increased with vacuum polymerization time and temperature in creasing. Meanwhile, the hydroxyl value decreased.
出处
《聚氨酯工业》
北大核心
2011年第5期5-8,共4页
Polyurethane Industry
关键词
聚碳酸酯二元醇
碳酸二乙酯
钛酸酯
酯交换
polycarbonate diols （PCDL）
diethyl carbonate
titanate
transesterification
