采用阳离子细乳液聚合，以八甲基环四硅氧烷( D₄ ) 为原料、十二烷基苯磺酸( DBSA) 为催化剂、乙烯基二甲基乙氧基硅烷( EDEV) 为封端剂制备分子链端含双键的聚硅氧烷中间体，以进一步合成疏水性能更好的硅丙乳液．考察了聚合温度、DBSA 用量、封端剂种类、EDEV 用量及EDEV 加入时间对 D₄ 单体转化率、产品粒径及其多分散指数( PDI) 的影响．结果表明: 聚合温度85 ℃、DBSA 用量6%、EDEV 用量 1．0%、聚合反应开始后3 h 加入EDEV 可得到粒径为95．3nm、PDI 为 0．123 的稳定有机硅细乳液聚合产品，单体转化率达92．1%; FT- IR 分析表明封端剂有效地参与了细乳液聚合反应; TEM 测试表明聚合物粒子为纳米结构．文中还建立了主要工艺参数对 D₄  阳离子细乳液聚合制备官能化聚硅氧烷的转化率影响的预测模型．

In order to synthesize silicone- acrylate emulsion with stronger hydrophobicity,polydimethylsiloxane endedwith vinyl terminal groups was synthesized via the cationic miniemulsion polymerization of octamethylcyclotetrasiloxane(D₄ ) monomer,with dodecylbenzene sulfonic acid (DBSA) as the catalyst and with ethenylethoxydimethyl silane(EDEV) as the blocking agent.Then,the effects of polymerization temperature,DBSA dosage,blocking agenttype,EDEV dosage and EDEV addition time on the monomer conversion rate,the latex particle radius and thepolydispersity index (PDI) were investigated.The results indicate that stable polymerization product of siliconeminiemulsion,which is of a radius of 95.3nm,a PDI of 0.123 and a monomer conversion rate of 92.1%,can beobtained via the polymerization at 85 ℃,with a DBSA dosage of 6%,an EDEV dosage of 1.0% and an EDEVaddition time of 3h.FT- IR results show that the blocking agent effectively takes part in the miniemulsion polymeri-zation.TEM analysis indicates that the product is in a nano- structure.Moreover,a model is proposed to predict the D₄ conversion rate of functional polysiloxane varying with the main technological parameters.