【摘要】 制备了以球形镁粉为原料的新型乙烯催化剂。通过扫描电子显微镜、激光粒度分析仪等分析和表征了催化剂及预聚物的形态及性能。结果表明:与采用片状镁粉为原料相比,采用球形镁粉为原料制得的预聚物的形态有所改善,流动性由-1级提高到1级。适于制备催化剂的球形镁粉粒径范围为30-70 μm,其活性可达313 mg/ (mol·h·Pa)。随着碘用量的减小,预聚物堆密度由0．28 g/cm3降至0．25 g/cm3,而预聚物的平均粒径由155．42μm提高到186．50 μm,细粉含量由27．1％降至14．8％。对预聚物的扫描电子显微镜观察表明,引入SiO2后预聚物形态接近类球形,流动性可达2级(优秀级别)。更多还原

【Abstract】 A series of novel high activity Ziegler-Natta catalysts were manufactured with spherical magnesium powder as the raw material. The morphology and properties of the catalysts and the prepolymer thereof were analyzed and characterized by scanning electron microscope (SEM) and laser particle size analyzer. The results indicate that the spherical Mg powder is favourable for the preparation of catalyst; the prepolymer prepared with the catalyst exhibit an improved morphology and fluidity, compared with catalyst made from laminar Mg powder. The activity of the catalyst manufactured with Mg powder in the particle size ranging from 30 to 70 μm can reach 313 mg/(mol·h·Pa). As the iodine amount is reduced, bulk density of the prepolymer decreases from 0.28 g/cm3 to 0.25 g/cm3 while the average particle size of the prepolymer increases gradually from 155.42 μm to 186.50 μm, in addition, the content of fine powder of the prepolymer lowered from 27.1% to 14.8%. The observation of the prepolymer under SEM demonstrates that the shape of the prepolymer particle approaches sphere and its fluidity reaches class Ⅱ (high class) after introducing SiO2 into the catalyst system.更多还原