用多官能引发剂体系合成丁基橡胶

Synthesis of butyl rubber with multi-functional initiator

采用双官能或三官能枯基氯为引发剂合成丁基橡胶,研究了引发剂体系的陈化时间和组分配比对聚合过程和聚合产物相对分子质量及其分布的影响。结果表明,二枯基氯或三枯基氯在烷基铝的作用下可以直接生成稳定的双端或三端形式的碳正离子活性中心,并进行链增长反应生成双臂线型或三臂星形大分子,最终制得相对分子质量较高、分子量分布较宽的丁基橡胶。引发剂体系及所得聚合物的质量都具有一定的稳定性。通过调整二氯乙基铝与二枯基氯的配比可以更容易地调节聚合物的相对分子质量及其分布,甚至获得相对分子质量呈双峰分布的丁基橡胶。

Butyl rubber（IIR） was synthesized by utilizing difunctional initiator dicumyl chloride （DCC） or trifunctional initiator tricumyl chloride （TCC） initiating system, and the effects of aging time and the ratio of components in initiating system on polymerization process, relative molecular mass and its distribution of the product IIR were investiga- ted. The results showed that DCC or TCC in conjunc- tion with ethyl aluminum dichloride （ EADC ） could directly generate stable difunctional or trifunctional C ＋ center which initiated a rapid polymerization of isobutylene and isoprene to lead to two-arm or three-arm star IIR with high relative molecular mass and broad molecular weight distribution. The IIR ob- tained was stable in its properties as well. Moreover, the relative molecular mass and its distribution of IIR could be regulated with varying mole ratio of EADC to DCC, and even IIR with bimodal molecular weight distribution was achieved under the condition of appropriate mole ratio of EADC to DCC.