连续循环管式反应器中丙烯酸丁酯的RAFT聚合研究

发布时间：2018-04-01 07:31

本文选题：RAFT聚合　切入点：环管反应器　出处：《浙江大学》2017年硕士论文

【摘要】：聚合物的分子量分布是影响其力学和加工性能的重要参数,如何通过反应器操作方式调控实现聚合物分子量分布的精确定制极具挑战。本文受工业环管反应器的启示,将其与可控“活性”自由基聚合技术相结合,进行多峰分子量分布聚合物的设计与定制。研究中以丙烯酸丁酯(BA)的甲苯溶液可逆加成-断裂链转移(RAFT)自由基聚合为模型体系,以3-苯甲基三硫代羧基丙酸(BCPA)为RAFT试剂,分别研究了 BA的间歇、连续管式及连续环管反应器中RAFT溶液聚合的反应动力学规律,揭示通过可调节管内单程停留时间和循环分率实现对聚合物多峰分子量分布的精确调控技术。研究表明管式反应器具有较好的传热传质能力,可有效地抑制间歇RAFT聚合中常见的诱导期,管内反应物能实现均匀混合从而减少扩散影响。连续环管反应器中,通过调控管内单程停留时间(τ)和循环分率,可定制具有预定多峰分子量分布的聚合物。不同循环分率的聚合体系经3τ后达到稳态且转化率基本不变,聚合物低分子量部分保持不变,而高分子量部分不断增大,该变化规律可通过理想高斯峰按几何分布的质量分率叠加模型得到定量解释。本工作率先提出了循环管式反应器与可控“活性”自由基聚合相结合的新技术,用于多峰分子量分布聚合物的设计与定制,其分子量分布可通过理想高斯峰按几何分布的质量分率叠加模型进行预测,这为连续地调控聚合物分子量分布进而生产可控多峰分布聚合物新材料提供了新思路。
[Abstract]:The molecular weight distribution of polymer is an important parameter that affects its mechanical and processing performance. How to realize the precise customization of polymer molecular weight distribution through reactor operation is a challenge.Based on the inspiration of industrial loop reactor, the design and customization of multi-peak molecular weight distribution polymer were carried out by combining it with controllable "active" radical polymerization technology.In this study, the batch of BA was studied by the reversible addition-break chain transfer radical polymerization of butyl acrylate (BA) in toluene solution as model system, and the use of 3-phenylmethyl trithiocarboxypropionic acid (BCPA) as RAFT reagent.The kinetics of RAFT solution polymerization in a continuous tube reactor and a continuous loop reactor reveals the precise control technology of polymer multi-peak molecular weight distribution by adjusting the one-pass residence time and cyclic fraction in the tube.The results show that the tubular reactor has good heat and mass transfer ability and can effectively suppress the common induction period in batch RAFT polymerization. The reactants in the tube can be homogeneously mixed and the diffusion effect can be reduced.In a continuous loop reactor, the polymer with predetermined multi-peak molecular weight distribution can be customized by regulating the one-pass residence time (蟿) and the circulation fraction in the tube.The polymerization system with different cyclic fraction reached steady state after 3 蟿 and the conversion was basically unchanged, the low molecular weight part of the polymer remained unchanged, while the high molecular weight part of the polymer increased continuously.The law of variation can be quantitatively explained by the mass fraction superposition model of the geometric distribution of the ideal Gao Si peak.In this work, a new technique of combining the cyclic tubular reactor with controllable "active" radical polymerization is proposed, which can be used in the design and customization of multi-peak molecular weight distribution polymers.The molecular weight distribution can be predicted by the superposition model of mass fraction of ideal Gao Si peak according to geometric distribution, which provides a new idea for the continuous regulation of polymer molecular weight distribution and the production of new polymer materials with controllable multi-peak distribution.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631.5

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