【作者】 李洪泊；

【导师】 孙建中； 刘青； 翁志学；

【作者基本信息】 浙江大学 ， 化学工程， 2003， 博士

【摘要】 本文以锂系阴离子溶液丁苯连续聚合过程为研究对象，在建立丁二烯／苯乙烯阴离子连续溶液共聚合模试装置的基础上，对以正丁基锂(n-BuLi)、四氢呋喃(THF)和环己烷分别为引发剂、调节剂和溶剂的丁二烯／苯乙烯阴离子连续溶液共聚进行实验研究，合成了丁苯无规共聚物并对产物进行了表征。详细考察了极性添加剂、物料平均停留时间及聚合温度等对共聚反应转化率、共聚产物微观结构、分子量及分子量分布的影响。在实验研究的基础上，建立了连续搅拌釜式反应器中丁二烯／苯乙烯阴离子溶液共聚合数学模型并进行了模型的参数估计和模拟计算。研究了阴离子活性种动态平衡行为对分子量分布的影响。本文还对连续搅拌釜式反应器液位波动对阴离子聚合过程的影响、反应器参数灵敏度及动态行为进行了深入的研究。 共聚合实验研究结果表明，提高THF／n-BuLi比值可明显增加丁二烯／苯乙烯阴离子连续共聚反应速度，但当THF／n-BuLi比值达到70左右后这种增加趋势变缓。随着THF／n-BuLi比值的增加，共聚物中的结合苯乙烯含量明显增加，1，2结构含量增加，而1，4结构含量减少，当THF／n-BuLi比值达到34左右后这种变化趋势开始减缓。随着物料平均停留时间的增加，单体转化率明显增加，共聚产物的分子量增加。平均停留时间的变化对共聚产物的微观结构及分子量分布的影响不显著，共聚产物的分子量分布指数接近于2。提高反应温度可显著增加聚合反应速度，反应动力学常数与温度的关系符合阿累尼乌斯方程。 由完全混合全混流和单一活性种假设，建立了连续搅拌釜式反应器中丁二烯／苯乙烯阴离子溶液共聚合数学模型。模型给出了共聚反应转化率和共聚产物分子量分布的各阶矩。结合实验结果对模型进行参数估计，求取得到反应动力学常数。在此基础上，对共聚反应转化率和共聚产物分子量及分子量分布进行了模拟计算。模拟结果与实验结果相符合。模拟分析还 浙江大学博士学位论文表明，引发反应为瞬间反应时，单体的转化率与丁二烯/苯乙烯的进料摩尔浓度_比和平均停留时间与引发剂进料浓度的乘积有关。 连续搅拌釜式反应器(CSTR)中反应物料的液位波动对阴离子聚合过程影响的模拟结果表明，在阴离子连续聚合过程中，CSTR中物料的液位波动将导致流出物料中单体浓度、聚合物分子链长及其分布的同周期波动，但单体浓度、聚合物分子链长及其分布指数的平均值与稳态值相比其差别很小，且波动幅度相对于平均值的比例也很小，阴离子连续聚合过程对csTR的液位波动不敏感，平均停留时间越长，反应器液位波动对阴离子连续聚合的影响越小。 用概率与统计方法建立了阴离子活性种多状态动态平衡系统中活性种处于各种状态的累积时间分布函数，量分‘布的方法。数值计算结果表明，并给出了用该函数计算聚合产物分子聚合物活性种不同状态增长反应活性差异越大，分子量分布越宽;活性种状态间转换速度越快，分子量分布越窄。 反应器参数灵敏度模型化研究和模拟分析表明，在CSTR中实施丁二烯/苯乙烯阴离子连续溶液共聚合时，存在反应温度对操作参数的敏感区域;反应器动态行为的理论分析表明，丁二烯/苯乙烯阴离子连续溶液共聚合存在多重解和周期解现象。在适宜的引发速度条件下，其解为稳定极限环，随引发速度的增加，极限环消失，解由稳定极限环变成稳定焦点。更多还原

【Abstract】 The anionic solution copolymerization of butadiene/styrene with n-butyllithium(n-BuLi) initiator, tetrahydrofuran(THF) modifier, and cyclohexane solvent was studied experimentally in an agitated tank reactor of 2 liters employing the continuous operation mode. The reaction conversion of comonomers, the molecular weight and molecular weight distribution of butadiene/styrene copolymer, and the micro-structure of the copolymer were analyzed by gas chromatograph, gel permeation chromatograph, and nuclear magnetic resonance, respectively. The effects of the mean residence time, the ratio of THF to n-BuLi(THF/n-BuLi), and the reaction temperature on the conversion, the molecular weight and molecular weight distribution, and the micro-structure of the copolymer were investigated. On the basis of the information of experimental study, models of comonomer conversion, and the molecular weight distribution under the condition of the maximum mixednees in a continuous stirred tank reactor(CSTR) were established. The parameters of the models were evaluated in terms of experimental data and the simulations of the models were carried out. Modeling of dynamic equilibrium of different states of living polymer was studied. The effects of dynamic equilibrium performance on the molecular weight distribution were simulated. In this thesis, the effects of the reactant level perturbation in CSTR on the anionic continuous polymerization, the analysis of parametric sensitivity of CSTR, and its dynamic performance were also studied.The experimental results showed that the effects of THF/n-BuLi on the rate of the anionic continuous solution copolymerization of butadiene/styrene, the content of combined styrene, and the micro-structure of the randomized copolymer of butadiene/styrene were significant, and that the effects of the mean residence time on the micro-structure and the molecular weight distribution of the copolymer were not remarkable, and that the effects of the mean residence time and the reaction temperature on the copolymerization rate were significant. The rate of the copolymerization increased obviously with increasing of THF/n-BuLi. The reasonable THF/n-BuLi was found to be 70. The content of combined styrene and the 1,2-structure of the copolymer increased and 1,4-structure decreased with increasing of THF/n-BuLi. This changes become slow when THF/n-BuLi reached about 35. The conversions of comonomer and the average molecular weight increased with increase of the mean residence time. The dispersion index of molecular weight distribution was close to 2.On the basis of the hypotheses of maximum mixedness and one active species, a mathematical model of the anionic solution copolymerization of butadiene/styrene in a CSTR, which included the conversion of the copolymerization and the moments of molecular weight distribution of the copolymer, was established. The reaction rate constants were obtained in terms of the experimental results and the parameter evaluation. The simulation of the conversions of the comonomers and the molecular weight and molecular weight distribution were carried out. The simulated results were good agreeable to the experimental results.The simulated results of the effects of the reactant level perturbation in CSTR on the anionic polymerization showed that for the anionic continuous polymerization the perturbation of reactant level in CSTR would lead to the oscillations of the monomer concentration and the polymer chain length and its distribution in the outlet steam with the same frequency as that of the reactant level perturbation. However, the differences betweenthe average values of the monomer concentration, the polymer chain length, its distribution, and the corresponding values of steady state were very small. The ratios of their amplitudes to the average values were much smaller than that of the reactant level perturbation. The anionic continuous copolymerization of butadiene/styrene is insensitive to the reactant level perturbation. The longer the mean residence time is, the more更多还原