A systematic investigation is carried out on the gas phase of propylene during the initial instants of polymerization. The results confirm the positive impact of small amounts of mineral oil on the initial reaction rate and morphology. It is shown that polymerizing under conditions of mild temperature and pressure alone are not enough to achieve the same result. It is found that the presence of mineral oil, and low temperature of polymerization can be used to control the morphology of polymer particles and to obtain high activity in the main reaction. If enough oil is used, moderate to high temperatures of prepolymerization are acceptable in terms of controlling morphology but can compromise the activity of the main polymerization. It is also observed that the way in which the oil is introduced has an impact on the kinetics and particle morphology. Separate addition of oil from the precatalyst gives rise to relatively flat kinetics during prepolymerization and highest rate during main polymerization. To account for the activity enhancement, a selective quench‐labeling study employing methyl propargyl ether shows that the presence of mineral oil appears to increase the fraction of active titanium by a factor of almost 2.

中文翻译：

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丙烯气相预聚合影响的实验研究

在聚合初期，对丙烯的气相进行了系统的研究。结果证实了少量矿物油对初始反应速率和形态的积极影响。结果表明，仅在温和的温度和压力条件下进行聚合是不足以实现相同结果的。发现矿物油的存在和低聚合温度可用于控制聚合物颗粒的形态并在主要反应中获得高活性。如果使用足够的油，就控制形态而言，中等至高温的预聚合是可以接受的，但会损害主聚合的活性。还观察到，引入油的方式对动力学和颗粒形态有影响。从预催化剂中单独添加油会在预聚合过程中产生相对平稳的动力学，在主聚合过程中产生最高的速率。为了说明活性的增强，一项使用甲基炔丙基醚的选择性淬灭标记研究表明，矿物油的存在似乎使活性钛的比例增加了近2倍。