以聚丙二醇二苯甲酸酯为给电子体的丙烯聚合催化剂

A Propylene Polymerization Catalyst Using Poly (propylene glycol) dibenzoate as Electron Donor

采用聚丙二醇二苯甲酸酯(PPGDB)为内给电子体制备了一种新的丙烯聚合催化剂MgCl2/PPGDB/TiCl4.该催化剂用于丙烯聚合时,除了具有与以邻苯二甲酸二异丁酯为给电子体的催化剂相当的活性和立体定向性外,其特点在于所得产物的分子量分布较宽(Mw/Mn>8.0).采用红外光谱研究了催化剂中PPGDB与MgCl2的作用机制,结果表明PPGDB中的酯官能团和醚官能团可同时与MgCl2配位.这种双官能团的配位作用是所得聚合物分子量分布较宽的主要原因.

A novel MgCl2-supported Ziegler-Natta catalyst using poly（propylene glycol）dibenzoate （PPGDB） as the internal electron donor for propylene polymerization was prepared. The catalyst exhibited comparable activity and stereoselectivity with that using normal phthalate as electron donor but rather broader molecular weight distribution of resulting polypropylene. Examination of the interaction between PPGDB and MgCl2 by using in- frared spectroscopy showed that both C=O and C-O-C of PPGDB could coordinate to MgCl2. This bidental coordination nature of PPGDB was suggested to be the reason for wide molecular weight distribution of the polypropylene obtained.