自由基悬浮聚合制备阳离子交换树脂的改进研究

Improvement of Preparation of Cation Exchange Resin by Free Radical Suspension Polymerization

本实验是基于高分子化学基础实验合成阳离子交换树脂所作出的创新性改进。实验中得到的聚乙烯基苯磺酸可用于离子交换,但是所得微球的粒径分布广泛,孔径分布少且不均匀,离子交换效率不高。在此基础上我们做出相应改进:在单体苯乙烯和二乙烯苯中溶入质量分数1%的线性聚苯乙烯,制备得到混有线性苯乙烯的交联树脂微球。用乙酸乙酯溶出线性苯乙烯后微球中存在大量空隙,磺化后可以引入更多的磺酸基团,使得离子交换的比表面积大幅增加。用偏光显微镜对改进方法制备的树脂微球进行形貌结构,观察到大量均匀的微孔。傅里叶红外光谱测试表明微球中含有更多的磺酸基。实验时长基本不变,所得产物离子交换效率提升了27%。以制备所得微球的离子交换效率作为实验评价机制,加入线性苯乙烯使用日常生活中常见的泡沫板,遵循绿色化学的理念,与生活联系紧密且更富趣味性,引导学生思考利用所学知识解决现实生活中的问题,实现理论和实践的统一。

Innovative improvements were proposed on the synthesis of cation exchange resin in the Basic Experiments of Polymer Chemistry.The polyvinylbenzenesulfonic acid obtained in the experiment can be used for ion exchange while the obtained microspheres have inconsistent hole size,a wide particle size distribution and a minor pore size distribution,leading to the low exchanging efficiency.Improvements were applied to this experiment:the cross-linked resin microspheres mixed with linear styrene were prepared with the linear polystyrene dissolved in the monomeric styrene and divinylbenzene.Then the linear styrene was dissolved with ethyl acetate.The specific surface area of ion exchange is greatly increased as there are a large number of voids in the microspheres.Finally more sulfonic acid groups are introduced.The morphology and structure of the resin microspheres prepared by the new method was characterized by polarized light microscopy.A large number of uniform micropores were observed.Fourier infrared spectroscopy showed that sulfonic acid was introduced to the microsphere.The ion exchange efficiency of the obtained product was increased by 27.3%with the critical time.The ion exchange efficiency of the prepared microspheres can be used as an experimental evaluation mechanism.Following the concept of green chemistry,linear styrene was obtained from the foam board commonly used in daily life.This experiment is closely related to life and more interesting,guide students to use knowledge to solve problems in life and realize the unity of theory and practice.