钕系催化剂和阳离子催化剂原位合成环化聚丁二烯

Synthesis of cyclized cis-1,4-polybutadiene in-situ by Nd-based catalyst and cationic catalyst

由丁二烯出发,在高的顺式聚合物收率下,钕系催化剂和阳离子催化剂可原位合成环化聚丁二烯(CPB)。由新癸酸钕、氢化二异丁基铝[Al(i-Bu)2H]和一氯二异丁基铝组成的均相催化剂在甲苯溶液中、聚合温度为50℃的条件下聚合丁二烯,当聚合物收率达到80%后,加入叔丁基氯(RCl),可原位引发聚丁二烯的阳离子环化反应。考察了聚合时间、丁二烯质量浓度和RCl/Al(i-Bu)2H(摩尔比)对原位环化反应的影响。结果表明,环化反应可在丁二烯质量浓度为0.05g/mL时进行;调节丁二烯质量浓度,可获得数均相对分子质量为4500～12000的CPB;调节RCl/Al(i-Bu)2H,可获得环化度为17%～55%的CPB。

Cyclized cis-1,4-polybutadiene （ CPB ） was synthesized in-situ by Nd-based catalyst and cationic catalyst from butadiene at cis-polymerization yield more than 80%. The homogeneous catalyst which was composed of Nd （ vers ） 3, Al （i-Bu）2H and AI（i-Bu） 2Cl, polymerized butadiene in toluene at 50 ℃ to a high yield polymer over 80 % ; then, t-BuCl was added to induce the cationic cyclization to afford a soluble cyclized polymer. The effects of the polymerization time, the concentration of butadiene and the amount of t-BuC1 on the cyclization in-situ were investigated. The results showed that cyclization in-situ could proceed at butadiene mass concentration 0.05 g/mL. The relative molecular mass of CPB could be controlled from 4 500 to 12 000 by varing mass concentration of butadiene. The degree of cyclization of CPB of 17% -55% could be acquired by varing of RCl/AI（i-Bu） 2H （ mole ratio）.