酚钾盐为助引发剂的异戊二烯调聚链转移反应研究

为开发阴离子调节聚合的新型助引发剂,克服现有助引发剂制备不安全、输送不方便的缺陷,更好地实现聚合产物相对分子质量及结构的设计,对以正丁基锂为引发剂、对甲基苯酚钾为新型助引发剂、二甲苯为溶剂兼做链转移剂、2G为极性调节剂的异戊二烯阴离子调聚链转移反应进行了研究.采用聚合瓶反应考察了ROK、2G和温度对链转移反应的影响,并求取了链转移次数、链转移常数、链转移速率常数及链转移反应活化能.结果表明,ROK的添加使体系发生了明显的链转移反应,2G的添加对链转移有促进作用.温度升高,链转移速率增大.

Study of chain transfer reaction of isoprene using potassium phenoxide as promoter

The development of a novel promoter in the anionic polymerization which is safer to prepare and more feasible to transport than the traditional one is necessary so that the designed relative molecular mass and structure are better realized. The chain transfer reaction of the anionic telomerization of isoprene with n-BuLi as the initiator, potassium para-methylphenoxide (ROK) as the novel promoter, xylene as the transfer agent as well as the solvent in the presence of 2G as the polar modifier was examined in polymerizing bottles. Effects of ROK, 2G and polymerizing temperature were studied. The chain transfer times and constant, chain transfer rate constant and the corresponding activation energy were also calculated. The results show that ROK can evidently accelerate the chain transfer reaction and 2G has some positive effect on it too. The increase of temperature can promote the chain transfer rate constant.