单分散苯乙烯-马来酸酐共聚物微球增长方式探究  

The nucleation and particle growth mechanisms of monodisperse microspheres of PSMA in self-stable precipitation polymerization

作　　者：郝国亮[1] 刘振杰[1] 邓建元[1] 杨万泰[1] 

机构地区：[1]北京化工大学化工资源有效利用国家重点实验室,北京100029

出　　处：《北京化工大学学报（自然科学版）》2010年第6期98-102,共5页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：长江学者和创新团队发展计划(IRT0706)

摘　　要：以丁酸乙酯为溶剂,AIBN为引发剂,采用自稳定沉淀聚合法于80℃下制备了单分散苯乙烯-马来酸酐(St-MAH)共聚物微球。对反应过程中不同反应时间的单体转化率、共聚物分子量、微球形貌及粒径进行了研究。结果表明,St-MAH共聚物微球粒径的3次方与转化率成直线关系,说明共聚物微球的聚合反应属于活性增长机理;同时提出自稳定沉淀聚合体系制备单分散St-MAH共聚物微球成核过程为AIBN在溶剂中引发苯乙烯和马来酸酐共聚生成寡居物,当寡居物链达到临界长度时从溶剂中沉淀出来,沉淀出来的寡聚物链相互缠绕形成球核;成核后单个微球所含St-MAH共聚物分子链数与时间的关系和转化率、微球粒径与时间的关系趋势大体一致,证实了自稳定沉淀聚合法制备St-MAH共聚物微球的增长主要是溶剂中形成的寡居物沉积于微球表面而实现的。Monodisperse microspheres of poly （styrene-co-maleic anhydride） （PMSA） have been prepared by self-stable precipitation polymerization at 80 ℃,with 2,2′-azobisisobutyronitrile （AIBN） as initiator and ethyl butyrate as solvent. The results showed that the cube of diameter （d3t） of the PSMA particles grew linearly with the polymerization conversion. When the PSMA chains were sufficiently long,they precipitated from the solution to form a nuclei of the particles. This suggests that the copolymer chains formed subsequently were adsorbed on the surface of the primary particles leading to increased size of the particles. A mechanism of the particle formation and growth has been proposed.

关 键 词：自稳定沉淀聚合 单分散聚合物微球 苯乙烯-马来酸酐共聚物 微球增长方式 

分 类 号：O631[理学—高分子化学]