1,3-二醇酯为内给电子体的丙烯聚合催化剂

研究了1,3-二醇酯为内给电子体的丙烯聚合ND-01系列催化剂的活性、氢调敏感性、定向性及动力学行为。实验结果表明,ND-01系列催化剂的活性较高;定向性易调;不加外给电子体时,所得聚丙烯的等规度也可达94.2%;与不同外给电子体配合使用的ND-01系列催化剂的性能与现有以邻苯二甲酸二丁酯为内给电子体的催化剂A的性能有较大的不同,使用二异丙基二甲氧基硅烷为外给电子体时,ND-01系列催化剂的氢调敏感性比催化剂A好,聚合所得聚丙烯的相对分子质量分布较宽;动力学行为实验结果表明,ND-01系列催化剂的活性衰减较慢。ND-01系列催化剂与三乙基铝/环己基甲基二甲氧基硅烷进行预络合反应时,ND-01系列催化剂中1,3-二醇酯的损失量小于催化剂A中邻苯二甲酸二丁酯的损失量。延长预络合时间,ND-01系列催化剂的聚合活性下降。

Propylene Polymerization Catalyst with 1,3-Diol Dibenzoate as Internal Donor

Activity,hydrogen response,stereospecificity and kinetic behavior of catalysts with 1,3-diol dibenzoate as internal donor for propylene polymerization were studied.1,3-Diol diester-based catalyst(ND-01)possessed high activity with slow decaying in propylene polymerization.Polypropylene obtained over the catalyst was controllable in stereospecificity with broad relative molecular mass distribution(MWD).Even without any external donors,the isotacticity of polypropylene obtained on 1,3-diol diester based ND-01 catalyst could reach 94.2%.The performance of ND-01 catalyst with various external donors were quite different from currently used catalyst A with n-butyl phthalate(DNBP)as internal donor.The hydrogen response behavior of ND-01 catalyst in polymerization with diisopropyl dimethoxy silane(DIPDMS)as external donor was excellent.Because 1,3-diol diester was more difficult to be extracted from catalyst by triethyl aluminum or triethyl aluminum/cyclohexylmethyl dimethoxy silane(AlEt_3/CHMDMS)than di-n-butyl phthalate(DNBP)therefore the loss lessened.The activity of ND-01 catalyst dropped with increasing of precontacting time with AlEt_3/CHMDMS.