以亚乙基桥联的反式二氯二茚锆（rac-（CH₂）₂Cp₂ZrCl₂）为催化剂，在改性甲基铝氧烷（MMAO）的活化下催化乙烯的均聚以及乙烯与正二十碳烯的共聚合反应。考察了反应温度、反应时间、MMAO用量、乙烯压力、二十碳烯浓度对聚合行为的影响。在乙烯均聚中，保持乙烯压力为0.1 MPa，当反应温度为50℃、反应时间为15 min、MMAO用量为催化剂的2 000倍时，催化剂活性最高，可达3.12×10⁷ g_PE/（mol_Zr·h），聚乙烯分子质量为112 kDa，分子质量分布为1.7。rac-（CH₂）₂Cp₂ZrCl₂所制备的聚乙烯熔点为133~135℃，为高密度聚乙烯。在乙烯与二十碳烯共聚中，rac-（CH₂）₂Cp₂ZrCl₂的催化活性低于乙烯均聚中的催化活性，随着二十碳烯浓度增加，所制备聚合物的支化度提高，熔点下降，结晶度下降，力学强度降低，断裂伸长率提高。

Under the activation of modified methylaluminoxane (MMAO),the homopolymerization of ethylene and the copolymerization between ethylene and eicosene are catalyzed by rac-(CH₂)₂Cp₂ZrCl₂.The effects of reaction temperature,reaction time,dosage of MMAO,ethylene pressure and concentration of eicosene on the polymerization are studied.In the ethylene homopolymerization process,the catalyst shows the highest activity as 3.12×10⁷ g_PE/(mol_Zr·h) when reaction temperature maintains at 50℃,reaction lasts for 15 minutes,and the dosage of MMAO is 2,000 times that of the catalyst.The obtained polyethylene has a molecular weight of 112 kDa with a molecular weight distribution of 1.7,its melting points are in the range of 133-135℃,which is consistent with that of high-density polyethylene.In the copolymerization of ethylene and eicosene,the catalytic activity of rac-(CH₂)₂Cp₂ZrCl₂ is lower than that in ethylene homopolymerization.With higher eicosene concentration,the branching degree and elongation at break of the prepared polymer increases,but the melting point,crystallinity and mechanical strength decrease.

卜芃(1987-),女,硕士,讲师,研究方向为化工与化学,53503292@qq.com