为提高聚丙烯综合性能,采用原位聚合法,将Brookhart型的乙烯齐聚催化剂负载于有机蒙脱土片层间,与丙烯聚合CS-I催化剂(Ziegler-Natta催化剂)进行复配,催化乙烯齐聚以及丙烯与乙烯齐聚产物进行共聚,制备聚丙烯/蒙脱土纳米复合材料.考察未负载与负载蒙脱土后的齐聚催化剂与CS-I复配的2类催化体系中聚合条件的影响,并通过XRD、透射电镜(TEM)、差示量热分析(DSC)、核磁(NMR)、凝胶渗透色谱(GPC)对聚合物进行分析表征.结果表明:齐聚、共聚反应条件对2类复配催化体系的活性、聚合物热力学行为、聚合物分子质量的影响很大;蒙脱土以纳米片层剥离的形式均匀分散于聚丙烯基体中,聚丙烯基体具有支化结构;均相复配催化体系得到聚合物的熔点由纯聚丙烯熔点161℃降低到135℃,而负载型的复配催化体系得到聚合物的熔点仅降低到148℃;聚丙烯/蒙脱土复合材料的分子质量为29×104~53×104 g/mol,分子质量分布范围为5.11~6.21.%In order to improve the performance of polypropylene, the Brookhart type of ethylene oligomerization catalyst was supported on the organic montmorillonite layer, and then mixed with propylene polymerization CS-I catalyst (Ziegler-Natta catalysts) to obtain the in-situ copolymerization catalytic system. Using the in-situ copolymeriza-tion, the polypropylene/montmorillonite nanocomposites were synthesized by the copolymerization of olefins/montmorillonite and propylene. Compared with homogeneous catalytic system and supported catalytic system, the effects of polymerization conditions were discussed. The polypropylene/montmorillonite composites were charac-terized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DSC), nuclear magnetic (NMR) and gel permeation chromatography (GPC). The results show that oligomerization and copolymerization conditions have signification effects on the polymerization activity and the thermodynamic be-havior and the molecular weight of the polymer in the two kinds of catalytic systems. Montmorillonite is uniformly dispersed in the polypropylene matrix in the form of nanosheet stripping, and the polypropylene matrix has a branched structure. The melting point of the copolymer catalyzed homogeneous catalytic system is reduced from 161℃to 135℃compared with polypropylene, and the melting point of the supported compound system is only reduced to 148℃. The molecular weight of polypropylene/montmorillonite composites ranges from 29×104 to 53× 104 g/moL, and the molecular weight distribution is 5.11~6.21.
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