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在α-甲基苯乙烯(α-MS)与丁二烯(B)的环已烷溶液中,以油溶性双锂为引发剂,于50℃下经2h将B全部聚合,降温至0℃,加入少量六甲基膦酰三胺(HMPT),使α-MS聚合,即得到α-MS-B-α-MS三嵌段共聚物。实验表明,在0℃以下,HMPT能加速B负离子聚合转为α-MS的聚合。α-MS的聚合过程存在两个反应阶段:一是只有0.5h的快速阶段,一是其后的慢速阶段;并且分子量分散指数随转化率的升高而增大。所得样品具有-86℃和172℃两个T_g,在300℃时热失重小于2％。当Pα—MS嵌段含量小于63％时,PB嵌段为连续相;大于63％时,Pα—MS嵌段为连续相。
In a cyclohexane solution of α-methylstyrene (α-MS) and butadiene (B), B was wholly polymerized at 50 ° C. for 2 hours with oil-soluble bis-lithium as an initiator, and the whole was cooled down to 0 ° C. , A small amount of hexamethylphosphine triamide (HMPT) was added to polymerize α-MS to obtain α-MS-B-α-MS triblock copolymer. Experiments show that below 0 ℃, HMPT can accelerate the polymerization of B-anion to α-MS. There are two reaction stages in the polymerization of α-MS: one is a fast phase with only 0.5h, the other is a slow phase; and the molecular weight dispersion index increases with the conversion rate. The resulting sample has two T_g of -86 ° C and 172 ° C and a thermal weight loss of less than 2% at 300 ° C. When Pα-MS block content is less than 63%, the PB block is a continuous phase; when it is more than 63%, the Pα-MS block is a continuous phase.