在1,1-二苯基乙烯(DPE)存在下,以甲基丙烯酸甲酯(MMA)为初始单体,偶氮二异丁腈(AIBN)为引发剂,采用本体聚合法制备出含有DPE片段的大分子引发剂PMMA—DPE;然后以PMMA-DPE为引发剂,以苯乙烯(st)和马来酸酐(MAn)为共聚单体,乙酸异戊酯为溶剂,采用自稳定沉淀聚合法制备了单分散的聚(苯乙烯-马来酸酐)(Poly(St—alt—MAn))的微球。研究了PMMA-DPE的用量对聚合物微球的形态、粒径大小及分布的影响。采用FT-IR,UV-Vis,1H—NMR和GPC对产物的结构进行了表征,并用SEM观察了聚合物微球的形貌。结果表明,PMMA-DPE能够引发St和MAn的共聚合,随着PMMA-DPE用量的增加,聚合反应的转化率呈增大趋势,聚合物微球的粒径呈下降趋势,而粒径分布系数略有增大。
Poly( methyl methacrylate) (PMMA) oligomers containing 1,1-diphenylethene (DPE) structural units (PMMA-DPE) have been prepared by the bulk polymerization of methyl methaerylate (MMA) in the presence of DPE with azodiisobutyronitrile (AIBN) as initiator. Narrow-disperse poly ( styrene-alt-maleie anhydride) [ poly (St-air-MAn) ] microspheres were subsequently obtained by metastable precipitation polymerization of styrene (St) and maleic anhydride (MAn) initiated by the PMMA-DPE, with isoamyl acetate as solvent. The structure of the copolymer was confirmed by FT-IR,UV-Vis and 1H-NMR spectroscopy and GPC. The morphology and size of the mierospheres were observed by SEM. The effects of varying the amount of PMMA-DPE on the morphology, particle size and size distribution of the microspheres were investigated. When the mass percentage of PMMA-DPE (based on total monomer amount) increased, the conversion increased and the diameter of the mierospheres decreased, but the distribution of diameter increased slightly.