不同引发方式对环氧丙烷阴离子聚合的影响

以丙二醇、氢氧化钾为引发剂，引发环氧丙烷阴离子聚合，原料不同脱水方法对聚合引发效果进行了详细的分析和比较。结果表明，将丙二醇/冠醚较低温度下真空脱水，再加入KOH脱水，然后加入少量单体聚合，对聚合得到的低聚物进行高真空脱水，再以产物为引发剂，利用短链引发方式引发聚合得到的目标聚合物聚环氧丙烷，它具有相对分子质量高、相对分子质量分布窄的特点，且多分散系数可达到1.09。

Investigation on different initiation modes in the anionic polymerization of propylene oxide

Propylene oxide was polymerized with potassium hydroxide as catalyst and 1, 2-propylene glycol as ini- tiator. Different improved initiation modes were used in the polymerization. The results showed that higher rela-tive molecular mass and much narrower relative molecular mass distribution were obtained by using the initiation mode with the process as follows: First, vacuum dehydration at a lower temperature of 1, 2-propylene glycol/18-crown-6; Second, vacuum dehydration of 1, 2-propylene glycol/18-crown-6/KOH; Third, short chain initiator was formed by addition of a small amount of propylene oxide into the system then vacuum dehydrated at higher temperature; Finally, the dehydrated short chain initiator was used to initiate the polymerization of PPO. By using this initiation mode, PPO with MWD of 1.09, closer to monodispersion, was obtained.