Process for the preparation of crystalline vinylaromatic polymers with a predominantly syndiotactic structure which comprises polymerizing the vinylaromatic monomers in the presence of a catalytic system consisting essentially of:
a) a complex of titanium having the formula (I):
Ti(OCONRR')n (I)
wherein R and R', the same or different, represent a C1-C12 aliphatic radical or C6-C12 aromatic radical whereas n is an integer equal to 3 or 4;
b) a cocatalyst selected from aluminoxane and a compound of boron having formula (II):
BX1X2X3 (II)
wherein X1, X2 and X3, the same or different, represent a C1-C20 perfluorinated hydrocarbon radical.
制备主要具有
辛二烯结构的结晶
乙烯基芳香族聚合物的工艺,包括在催化系统存在下聚合
乙烯基芳香族单体,该催化系统主要由以下部分组成:
a) 具有式 (I) 的
钛络合物:
Ti(OCONRR')n (I)
其中 R 和 R'(相同或不同)代表 C1-C12 脂肪族基或 C6-C12 芳香族基,而 n 是等于 3 或 4 的整数;
b) 选自氧化铝和具有式 (II) 的
硼化合物的助催化剂:
BX1X2X3 (II)
其中相同或不同的 X1、X2 和 X3 代表 C1-C20
全氟烃基。