核壳型聚(丙烯酸丁酯/甲基丙烯酸十二酯)乳液的制备及表征

Synthesis and Characterization of P(BA/LMA) Polymer with Core-Shell Structure

以丙烯酸丁酯(BA)为核单体,甲基丙烯酸十二酯(LMA)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软核软壳结构的聚(丙烯酸丁酯/甲基丙烯酸十二酯)。采用复配比为2∶1的OP-10和十二烷基硫酸钠(SDS)复合乳化剂,采用乳化剂的质量分数为4%左右时的乳液稳定;壳单体的滴加速度在8 mL/h时,体系稳定,且转化率高。用FTIR分析了聚合物的结构。透射电子显微镜观察表明,交联剂交联场所不同形成的粒子的形态也不同即核层不加交联剂、核层加交联剂与核、壳层均加交联剂分别形成了球形、核壳结构和梅花形状的粒子;DSC分析表明,聚合物具有2个玻璃化转变温度Tg1=-64℃,Tg2=-51℃。

An acrylate polymer,P（BA/LMA）,with soft core-soft shell structure was synthesized by semi-continuous emulsion polymerization under monomer starved condition.Butyl acrylate was used as the monomer for the core and for lauryl methacrylate as the monomer for the shell.Ethylene glycol dimethacrylate was used as the crosslinking agent for the core.The result indicated that the system was stabilized at a ratio（OP-10/SDS） of 2∶1 and an emulsifier concentration of 4%.The monomer had a high rate of conversion at an addition rate of 8 mL/h.The structure of P（BA/LMA） was analysed by FT-IR.Presence of the crosslinking agent at different places led to different morphologies such as spheres（without crosslinking agent）,core-shell structure（with crosslinking agent in the core）,cinquefoil（with cosslinking agent in the core and the shell）.DSC indicated that the polymer had two Tg at-64 ℃ and-51 ℃,respectively.