采用偶氮对2-脒基丙烷盐酸盐（V-50）为引发剂通过无乳化剂乳液聚合方法制备尺寸均一的阳离子型聚甲基苯乙烯（PMS）胶乳粒子。详细讨论聚合条件,如引发剂浓度、单体浓度、离子强度、搅拌速度对聚合速率、粒子尺寸及分布的影响。最终获得制备单分散无乳化剂阳离子型聚甲基苯乙烯胶乳粒子的方法。

Controlled synthesis of aldehyde-functional poly(methystyrene) (PMS) latexes in an emulsifier-free system was achieved via an emulsifier-free emulsion polymerization of methylstyrene using V-50 as an initiator, followed byanin-situ surface oxidation catalyzed by copper(Ⅱ) chlorideandtert-butyl hydroperoxide. Our investigation of the effect of oxidant concentration, reaction time, and temperature demonstrated that controlling the surface concentration of aldehyde and carboxylic acid groups was readily accomplished by altering these three reaction parameters. The concentration of the catalyst, however, was found to have little affect on the rate of oxidation. Furthermore, the amounts of surface aldehyde and carboxylic acid groups were determined by conductometric and potentiometric titrations. Electrolyte stability of functionalized latexes was also examined with regard to their critical coagulation concentrations in various salt solutions. Finally,SEMstudies were conducted and clearly showed that surface morphology of functional latexes hardly altered with a low degree of oxidation but became aggregates when highly oxidized latexes were formed.

methylstyrene.PMS. latex particles in an emulsifier-free emulsion were first synthesized by using 2,29-azobis-2-amidinopropane. dihydrochlorideV-50. as an initiator. Purification of the latexes by dialysis was followed inorder to remove residual monomer, initiator and electrolytes. The cationic polymethylstyrene. latexes were then oxidized in the presence of t-butyl hydroperoxide catalyzed by copper chloride at 608C under air. The degree of oxidation increased with reaction time, but the emulsions of highly oxidized poly methylstyrene. latexes were found to be unstable. An increase of oxidant concentration enhanced the rate of oxidation, while the catalyst concentration had little influence on it. The effect of reaction temperature and pH value on the catalytic oxidation of poly methyl-styrene. latexes was also investigated.