Front Cover: Surface of a gas‐phase, prepolymerized polypropylene particle. Prepolymerizing in the presence of limited amounts of mineral oil allows one to obtain sustainably high activities and exert good control over the particle morphology. In article 1900052, Yue Yu and Timothy F. L. McKenna report that the oil plasticizes the nascent polymer, allowing the particles to retain a more regular shape during the fragmentation step.

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大分子 反应 。3/2020

前盖：气相预聚合聚丙烯颗粒的表面。在有限数量的矿物油存在下进行预聚合可以使人们获得持续的高活性，并对颗粒的形态进行良好的控制。在文章1900052中，Yu Yu和Timothy FL McKenna报告说，该油可塑化新生的聚合物，从而使颗粒在破碎步骤中保持更规则的形状。