核壳结构的P(BA/LMA-St)制备及表征

Preparation and Characterization of P(BA/LMA-St) With Core-Shell Structure

以丙烯酸丁酯(BA)为核单体,甲基丙烯酸十二酯(LMA)或LMA和苯乙烯(St)为壳单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用分阶段饥饿态加料方式和半连续乳液聚合方法合成了具有核壳结构的P(BA/LMA)和P(BA/LMA-St)2个乳液体系。讨论了壳单体的滴加速度对2个体系乳液性能的影响,结果表明加入St后壳单体的滴加速度提高,达到10 mL/h,体系稳定,转化率高;采用傅里叶变换红外分析了2个乳液体系的基团变化;差示扫描量热分析了2个体系的玻璃化转变温度,结果表明壳单体中加入苯乙烯体系的2个玻璃化转变温度均升高;激光粒度仪考察了2个体系乳胶粒的粒径分布,结果表明壳单体中加入苯乙烯后粒径分布变宽;透射电镜分析了2个体系的形态结构,结果表明壳单体中加入苯乙烯后聚合物仍是核壳结构的聚合物。

Two emulsion systems of P（BA/LMA） and P（BA/LMA-St） with core-shell structure were synthesized by using semi-continuous emulsion polymerization method and stepwise starved feeding way using butyl acrylate（BA） as core monomer,lauryl methacrylate（LMA） or both LMA and styrene（St） as shell monomer,ethylene glycol dimethacrylate（EGDMA） as crosslinking agent.The influence of shell monomer dropping speed on emulsion properties of two systems was investigated.The results show that the systems are stable and the conversion is high with shell monomer dropping speed increasing to 10 mL/h after adding St.The group changes of two emulsion systems were analyzed by FT-IR.The Tg of two emulsion systems was analyzed by DSC.The results show that two Tg of emulsion systems containing St in shell monomer all increase.The latex particle size distribution of two emulsion systems was investigated by laser particle analyzer（LPA）.The results show that the particle size distribution broadens after adding St into shell monomer.The morphology structures of two emulsion systems were analyzed by TEM.The results show that the polymer obtained after adding St into shell monomer is still a polymer with core-shell structure.