【作者】 张静；

【导师】 涂伟萍；

【作者基本信息】 华南理工大学 ， 化学工程， 2006， 博士

【摘要】 随着人们环保意识的增强和环境法规的逐步严格，涂料技术正处于快速的变更时期。新的技术需要新的原材料，其中反应性微凝胶就是当今发展起来的最有用的新型聚合物之一。反应性微凝胶由于其分子内交联的特殊结构，具有许多不同于其它聚合物的优异性能和功能，为涂料性能的提高开辟了新的有效途径。因此，对微凝胶的合成与应用进行深入研究有着十分重要的现实意义和理论意义。 本文在对前人和他人研究成果进行总结的基础上，分别采用乳液聚合、核壳乳液聚合和自稳定分散聚合法合成了丙烯酸酯类反应性微凝胶，并详细研究了微凝胶的性能及其应用。 采用乳液聚合方法合成了反应性微凝胶颗粒，研究了交联剂存在条件下的乳液聚合反应的动力学特征，并分析了交联乳液聚合中反应性微凝胶的形成机理。研究表明，乳化剂浓度、引发剂浓度以及交联剂用量等对乳液聚合动力学有较大的影响。与常规线形乳液聚合过程不同，在交联乳液聚合中，由于在聚合反应初期乳胶粒内部的交联度比较高，凝胶效应使得微凝胶形成的成核阶段就可以发生在胶束中和单体珠滴中，聚合反应的速率与乳化剂浓度成反比的关系；对反应过程粒径的跟踪分析表明，随着聚合反应的进行，微凝胶颗粒的粒径随着转化率的增加而线性增加，但粒径分布则变化不大。 根据粒子设计的新概念及官能团定位技术，采用核壳乳液聚合方法，制备得到了以反应性微凝胶为核、成膜性能良好的核壳结构的乳液，并分别在乳胶粒的核、壳层引入了可进一步发生交联反应的环氧基和羧基，通过红外光谱(FTIR)、透射电子显微镜(TEM)测定了乳胶粒的结构。研究表明，增加乳化剂用量或提高预乳化单体的滴加速度，降低交联剂三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)的用量均有利于聚合反应稳定性的提高。通过对反应性微凝胶乳液形成过程中凝聚物形成机理的探讨得出，聚合的单体珠滴、水溶性聚合物的架桥凝聚及其微凝胶颗粒上悬吊双键、官能性基团间的分子间交联反应是凝聚物形成的主要原因。 借助于Malvern粒度分析、差示扫描量热(DSC)分析、热失重(TG)分析、动态热力学(DMA)分析以及力学性能、流变性能的测试，研究了以反应性微凝胶为核的自交联型核壳结构乳液的性能及其涂膜性能。研究表明，这种核壳结构的微凝胶乳液具有非常优异的流变性能(如剪切变稀和触变性)，尤其适用于涂料的喷涂；且通过高温烘烤，两种基团发生了充分的交联，增强了核壳之间的结合强度和相容性，并提高了涂膜的综合性能。 本文还采用自稳定分散聚合方法，选用带有长疏水链的丙烯酸酯单体进行共更多还原

【Abstract】 With increasing consciousness for environmental protection and the reinforcement of environmental legislation, coating technology is in a fast development era. New coating technology requires new raw materials. Reactive microgels are one of the most useful new polymers. Due to their intramolecularly crosslinked structure, reactive microgels possess superior properties and functions, which offers a new approach to improve coating performance. Therefore, research on the synthesis and application of reactive microgels is of great practical and theoretical significance.Referring to other people’s research, the acrylate reactive microgels have been prepared using emulsion polymerization, core-shell emulsion polymerization, and self-stabilized dispersion polymerization. In addition, the properties and applications of the prepared reactive microgels have been studied.The reactive microgel was synthesized by the emulsion polymerization technique. Factors affecting kinetics of emulsion polymerization were discussed, and the nucleation mechanism of reactive microgel formation in crosslinking emulsion polymerization was investigated. Results show that emulsifier concentration, initiator concentration, and crosslinker concentration have great influence on the kinetics of emulsion polymerization. Compared to the previous results from linear emulsion polymerization, the crosslinking density is fairly high even from very early stage in crosslinking emulsion polymerization. So Nucleation of microgel formation can take place in both micelles, and monomer droplets and the polymerization rate is inversely proportional to the emulsifier concentration because of the gel effect. The study on the particle size in the synthesis process indicate that the particle size of microgels particles increases linearly with monomer conversion and the particle size distribution is still rather narrow with the progress of polymerization.Based on particle design theory and functional group localization technique, the latex with core-shell structure was prepared using the microgels as core and polymer with good film formability as shell. Besides, the reactive groups, i.e. epoxy and carboxyl groups are enriched in the core and shell region, respectively. The structure of the latex was finally characterized using Fourier Transform Infrared Ray spectrum (FTIR) and Transmission Electron Microscope (TEM). The results illustrate that,更多还原