【作者】 栗伟；

【导师】 李伯耿； 曹（方方土）；

【作者基本信息】 浙江大学 ， 化学工艺， 2002， 硕士

【摘要】 间规聚苯乙烯(sPS)是一种新型热塑性塑料，由于其优良的性能，使之成为近年来研究的热点。 本文采用CpTiX3／MAO／TIBA均相茂金属催化体系，针对苯乙烯间规溶液聚合、sPS悬浮液体系流变行为以及间规聚苯乙烯种子半连续聚合工艺开发做了系统的研究，得到以下结果： 在氯苯、甲苯、庚烷、异辛烷、十氢萘及混合溶剂中进行苯乙烯间规溶液聚合，证明一定范围内提高聚合温度、提高搅拌转速、降低溶剂极性、采用无定形聚苯乙烯的不良溶剂可以促进聚合的进行，提高苯乙烯单体转化率。同时，提高搅拌转速、降低聚合温度与溶剂极性可以提高聚合产物的分子量。 同时研究了在不同聚合条件下原生态sPS结晶动力学规律。并且发现溶液聚合中改变溶剂的性质，对sPS原生晶晶型不产生影响，始终是δ晶型。对溶液聚合sPS原生态粒子粒径与粒径分布的研究表明，提高聚合温度、强化搅拌作用，采用异辛烷、十氢萘作为聚合介质可以有效改善sPS粒子的颗粒形态。 研究了sPS的悬浮液体系的流变性质，发现在氯苯体系中固含量低时，体系为牛顿流体性质；提高悬浮液浓度，体系的非牛顿性加强，呈现剪切稀化特点。同时，在高浓度悬浮液中，温度升高可以降低体系的剪切应力和表观粘度。由无定形聚苯乙烯不良溶剂(如庚烷、异辛烷等)配制的悬浮液，固含量小于15％时，体系呈现牛顿流体性质。 在500ml立式聚合釜中成功实现了sPS种子半连续聚合，表明此工艺是可行的，能够有效防止本体聚合过程中复杂的相态更迭以及凝胶、聚合釜淤塞现象的发生，达到降低聚合功率消耗的目标。更多还原

【Abstract】 Syndiotactic polystyrene (sPS) is a new type of thermoplastics. Recently it becomes focus of research for its excellent properties.In the thesis, a homogenous metallocene catalyst system, Cp*TiX3/MAO/TIBA was used to prepare the syndiotactic polymer. The kinetics of the solution polymerization process, the particle morphology of the produced sPS, and the rheology of the sPS suspension were studied. A seeded semi-continuous polymerization process was investigated also.The styrene syndiotactic solution polymerization were carried out respective in the presence of chlorobenzene, tolune, heptane, isooctane, naphthane and mixed solvent. The results demonstrate that elevating the polymerization temperature and agitation speed, reducing polarity of solvent or using non-solvent for amorphous polystyrene are beneficial to polymerization and raise monomer conversion. And the molecular weight of produced polymer is increased with decrease in temperature and solvent polarity, and with an increase in agitation rate.The investigation on crystallization kinetics of nascent sPS shows that the crystal of nascent sPS from solution polymerization is in 6 type and does not change with variety of solvent. The data of particle size and particle size distributions of the produced polymer during the polymerization indicates that elevating polymerization temperature and agitation speed, and using isooctane or naphthane to be solvent will improve the morphology of nascent particles.By investigating the rheology of sPS suspension, we found that the sPS-chlorobenzene suspension has Newtonian fluid properties when the polymer content is lower than -10%. But suspension will be shear-thinned and turn into the Non-Newtonian fluid with an increase in the sPS content. When the solid content is relative high, temperature rising will decrease shear stress and apparent viscosity. However, when the suspension is prepared by a non-solvent for amorphous polystyrene, such as heptane and isooctane, and the sPS content is lower than 15%,the fluid is Newtonian.The seeded semi-continuous bulk syndiotactic polymerization of styrene is achieved in a 500mL reactor. During the polymerization process, the complicated phase change, the gelation and the reactor fouling can be avoided efficiently.更多还原