α—甲基苯乙烯离子聚合体分子量分布

聚α-甲基苯乙烯-丁二烯-α-甲基苯乙烯嵌段共聚物是一种性能优异的热塑性弹性体。常温下,α-甲基苯乙烯的聚合是在极性添加剂存在下进行的,添加剂的种类,用量及聚合温度不仅影响聚合动力学,尚且影响聚合物分子量及其分布,控制α-甲基苯乙烯聚合速率、

MOLECULAR WEIGHT DISTR IBUTION OF POLYALPHA METHYLSTYRENE

The molecular weight distribution of polyalpha-methylstyrene prepared by anionic polymerization, with n-butyllithium as initiator was investigated. The influences of ether additives, ratios of ether to initiator and polymerization temperature on the molecular weight distribution of polymers were studied.Thereactivity of reactive species and rate of interchange between the reactive species were considered as the main factors effecting the molecular weight distribution of the polymer.With increasing polymerization temperature and by using more strong and concentrated ether additive the molecular weight distribution of the polymer became more narrow.