【作者】 黄源；

【导师】 李伯耿；

【作者基本信息】 浙江大学 ， 化学工程， 2003， 博士

【摘要】 本文从多相多组分本体聚合过程的角度出发，研究了橡胶接枝苯乙烯—马来酸酐本体无规共聚合过程的聚合动力学、相转变规律及共聚物组成和橡胶相结构的控制规律。采用半连续和连续聚合工艺成功制备了耐热和抗冲性能优良的橡胶增韧苯乙烯—马来酸酐无规共聚物(R-SMA)树脂。 通过橡胶和接枝物中双键结构和含量的分析确定了热引发和化学引发方式下低顺式聚丁二烯橡胶和高顺式聚丁二烯橡胶的接枝反应机理，并通过聚合过程中真实接枝率和表观接枝率随转化率变化的研究探明了橡胶相尺寸对接枝反应的影响。 系统研究了半连续聚合过程的橡胶含量、橡胶种类、反应温度、引发剂浓度、马来酸酐含量、滴加速率、溶剂用量和搅拌转速等因素对聚合体系相分离和相转变过程的影响。指出相分离过程是一个热力学过程，相分离点主要由温度、组成等因素决定；相转变过程则是一个动力学和热力学共同作用的过程，体系的组成、温度、粘度和剪切强度等因素则都对其有重要的影响。 在深入理解该多相多组分聚合过程相转变行为的基础上，首次采用两种Monte Carlo模型——稳态模型和动态模型，来模拟聚合体系的相转变过程。稳态模型的参数虽然没有明确的物理意义，但却能给出相转变过程的起点和终点；动态模型则从液液分散理论出发，综合考虑搅拌强度、体系粘度和密度、界面张力、接枝效率及相体积分率等因素的影响，能很好的预测相转变的起点，略加改进后该模型可以用于相转变的全过程模拟。 首次提出了橡胶接枝苯乙烯及苯乙烯—马来酸酐的非均相本体聚合动力学模型。实验和模拟研究表明，引发剂的笼蔽效应、橡胶初级自由基的活性较低是橡胶加入后聚合速率下降的主要原因。但加入粘度较高的橡胶后引起的聚合体系凝胶效应将导致聚合速率增加。不同的橡胶，由于其结构和粘度的差异对聚合速率的影响不同。 系统研究了橡胶含量、反应温度、引发剂浓度和引发方式、滴加速率、马来酸酐用量、溶剂用量和搅拌条件等工艺条件对橡胶接枝苯乙烯—马来酸酐本体半 摘 要连续聚合动力学的影响。研究发现MAH的补加速率是控制聚合速率和产品中MAH含量的主要因素。升高温度、增加溶剂用量和降低马来酸配含量等有利于减少体系中电子转移络合物（CTC）的因素均利于树脂共聚物组成的均一。非均相聚合动力学模型对橡胶接枝苯乙烯一马来酸团本体半连续聚合过程模拟结果表明，当聚合条件有利于减弱CTC的形成时，模拟结果与实验值较吻合，否则误差较大。 系统剖析橡胶增韧R－SMA树脂的微观结构对冲击性能的影响。发现真实接枝率较低时，树脂的冲击性能随真实接校率的增加而增加，当真实接枝率大于120以后，树脂的冲击性能只决定于橡胶相粒径及其分布，但树脂的最佳橡胶粒径随基体树脂中MAH含量的增加而增加。 详细考察了操作方式、开车方式、搅拌转速和停留时间对橡胶接枝苯乙烯一马来酸研连续聚合过程中共聚物组成和接校率的影响，分析了连续聚合与半连续聚合产物橡胶相形貌的差异，总结出最佳的连续聚合工艺，成功地制备了性能优良的抗冲级R－SMA树脂。更多还原

【Abstract】 In view of the multi-phase multi-component bulk polymerization, kinetics, phase inversion, control and optimum of composition and structure of grafting copolymerization of styrene-maleic anhydride onto rubber have been studied. Good heat resistant and impact resistant rubber modified random copolymer of styrene and maleic anhydride (R-SMA) resin is prepared by semi-batch and continuous processes.The mechanisms of grafting reaction of styrene onto low-cis and high-cis polybutadiene by thermal and chemical initiations are investigated by analysis of the micro-structures of rubber and their grafting copolymer. And the effect of rubber phase on grafting reaction is studied by examining the evolution of the true and the apparent grafting ratios in polymerization process.The effects of polymerization conditions, such as rubber content and varieties, reaction temperature, ratios of monomer/co-monomer/initiator/solvent, inflow rate of co-monomer and agitation conditions etc., on the phase behavior have been discussed in detail. It is concluded that phase separation is determined by the thermodynamic equilibrium, and related with temperature and compositions, while the phase inversion is operated by the thermodynamic and the dynamic behaviors, determined not only by temperature and compositions, but also by viscosity and agitation.On the basis of analysis of experimental results, two Monte-Carlo models, steady model and dynamic model, have been presented to simulate the phase inversion process. The steady model is able to predict the start and the end points of the phase inversion, although the model parameters have no distinct physical meanings. The factors, such as agitation strength, density, viscosity, interfacial surface tension, grafting efficiency and volume fraction etc., have been considered in the dynamic model, which can predict the start point of phase inversion successfully.A new heterogeneous model has been developed to simulate the kinetics of bulk graft copolymerization of styrene onto rubber. Experimental data and simulation results showed that cage effect of initiator and low reactivity of rubber radical are keyfactors of reduction of polymerization rate in presence of rubber. The polymerization rate is also affected by gel effect when the higher viscosity rubber is used. Different effects on polymerization rate are given by different rubbers because of their disparity of structure and viscosity.The copolymerization kinetics and copolymer composition for semi-batch graft copolymerization of styrene and maleic anhydride onto rubber under various conditions have been investigated. It is concluded that the inflow rate of comonomer is the key factor of polymerization rate and maleic anhydride content. The factors, which lead to reduction of charge transfer complex (CTC), are contributed to decreases of polymerization rate and MAH content. The heterogeneous model has been used in simulation of semi-batch graft copolymerization of styrene and maleic anhydride onto rubber. It is found that simulation results are good agreed with experimental data when it is difficult for CTC to exist.The relationship between microstructure of rubber with impact strength of resin is investigated. The toughness increases with the true grafting ratio (TGR) in lower TGR. And it mainly depends on the size and size distribution of rubber phase when TGR is more than 120. The more the MAH content in matrix resins, the bigger rubber particle is required.The influences of operation methods, start-up policies, agitation condition and residence time on performance of the continuous graft copolymerization of styrene and maleic anhydride onto rubber and the difference in the morphology of rubber phase between semi-batch and continuous polymerization processes have been investigated also. A proper continuous technology has been select to prepare the high performance impact R-SMA.更多还原