酸碱溶胀法制备聚合物中空微球的研究

Study on the synthesis of polymeric hollow microspheres through acid-alkali swelling method

采用种子乳液聚合的方法合成了核壳结构的poly(methyl methacrylate)/polystyrene(PMMA/PS)和poly(butyl acrylate)/polystyrene(PBA/PS)微球,并以此作为前驱体,利用酸碱溶胀法成功地制备出PS中空微球.采用TEM和SEM对核壳微球和中空微球的形貌进行了表征,并研究了中空结构形成的影响因素.结果表明,在壳层单体St包裹种子微球的聚合阶段,单体和引发剂的滴加速度及温度对最终的PS中空微球形态有着显著的影响:滴加速度过慢,反应温度过高均不利于中空微球的形成.另外,组成种子微球的单体和壳层单体的性质对中空微球的形态也有着较大的影响.

Core-shell structured poly （methyl methacrylate）/polystyrene （PMMA/PS） and poly （butyl acrylate）/polystyrene（PBA/PS） microspheres were synthesized through seeded emulsion polymerization. PS hollow microspheres were successfully obtained subsequently through an acid-alkali swelling process using the core-shell structured microspheres as the precursors. The morphologies of the core-shell structured microspheres and hollow microspheres were investigated by TEM and SEM. A variety of factors, which way influence the formation of core-shell and hollow structures, were studied. The results show that, the polymerization temperature and the dropping rate of monomers and initiators are both significant in controlling the latex particle morphology at the stage of encapsulation. An excessively low dropping rate of the shell monomers and an excessively high polymerization temperature are unfavorable for the formation of hollow microspheres. The natures of monomers constituting seed microspheres and shell also have an impact on the morphology of hollow microsphere.