新型复合外给电子体SED 2530对Ziegler-Natta催化剂催化丙烯聚合的影响

以丙烯为原料,CS-Ⅰ为主催化剂,三乙基铝为助催化剂,分别以环己基甲基二甲氧基硅烷(Donor-C)、二环戊基二甲氧基硅烷(Donor-D)及二者混合物或烷氧基硅烷(SED 2530)为外给电子体,在反应温度为70℃,反应压力为4.0 MPa,物料平均停留时间为1.1~1.5 h的条件下,制备了聚丙烯(PP)粉料;将其与抗氧剂1010、抗氧剂168及硬脂酸钙混合造粒,制备出了PP树脂。结果表明,由SED 2530制备的PP树脂熔体流动速率、等规度、热变形温度和结晶温度依次为4.099 g/min,99.5%,118.3℃,123.3℃;此外,其弯曲应力为1 826 MPa,拉伸屈服强度为38.1 MPa,均高于由其他几种外给电子体制备者,表明以SED 2530为外给电子体的催化体系具有良好的氢调敏感性及更好的刚韧平衡性。

Effect of a novel composite external donor on propylene polymerization over Ziegler-Natta catalyst

Polypropylene （PP） powder was prepared with propylene as raw materiaI,CS -I as main catalyst, triethylalu- minum as coeatalyst and using cyclohexyl methyl dimethoxysi- lane （ Donor - C）, dieyelopentyl dimethoxysilane （ Donor - D ） and their mixture or alkoxy silane（ SED 2530）as external electron donor respectively at temperature 70 ℃,pressure 4.0 MPa and average residence time 1.1 - 1.5 h. And PP resin was prepared by mixing granulation of PP powder, antioxidant 1010, antioxidant 168 and calcium stearate. The resuhs showed that the melt flow rate,isotaetieity, heat distortion temperature and crystallization temperature of PP resin prepared with SED 2530 were 4.099 g/min,99.5% , 118.3 ℃ , 123.3℃ respectively, and the bending modulus and the tensile yield strength of the resin were 1 826 MPa, 38.1 MPa separately, higher than those with the other external donors, indicating that the catalyst system with SED 2530 as external donor bad good hydrogen response and rigid- tough balance.