Understanding and preventing the formation of deformed polymer particles during synthesis by a seeded polymerization method
Understanding and preventing the formation of deformed polymer particles during synthesis by a seeded polymerization method
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DOI：
10.1002/pola.24636
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发表时间：
2011-05
期刊：
影响因子：
--
通讯作者：
Anong Srisopa;A. Ali;A. Mayes
中科院分区：
文献类型：
--
作者：
Anong Srisopa;A. Ali;A. Mayes
采用种子聚合法制备了不同极性的聚二乙烯基苯、聚醋酸乙烯酯-二乙烯基苯、聚二甲基丙烯酸乙烯酯和聚甲基丙烯酸缩水甘油酯-二甲基丙烯酸乙烯酯的微米级多孔聚合物颗粒。影响粒子形态的参数，包括单体混合物含量，致孔剂含量，和聚苯乙烯（PS）种子胶乳是不同的，所得粒子的形态进行了研究，通过扫描电子显微镜和共聚焦显微镜。结果表明，粒子形状主要取决于PS种子模板的分子量。当使用高分子量PS种子时，获得变形颗粒，包括塌陷的球体和具有孔的球体，而通过使用低分子量种子容易地产生定义明确的聚合物颗粒。使用1，1-二苯基乙烯作为链终止剂在种子聚合过程中，提出了在这项工作中作为一种有效的方法，以降低种子颗粒中的PS分子量，同时保持种子尺寸小。该低分子量种子模板在与不同的第二阶段单体溶胀和聚合后保持其球形几何形状。
Uniformly sized porous polymer particles with different polarity namely poly(divinylbenzene), poly(vinyl acetate-co-divinylbenzene), poly(ethylene dimethacrylate), and poly (glycidyl methacrylate-co-ethylene dimethacrylate) were prepared in the micron-size range by a seeded polymerization method. Parameters affecting the particle morphologies including monomer mixture content, porogen content, and polystyrene (PS) seed latexes were varied, and the morphologies of the resulting particles were investigated by scanning electron and confocal microscopy. The results obtained indicated that the particle shape depended dominantly on the molecular weight of the PS seed template. Deformed particles, including collapsed spheres and spheres with holes were obtained when high molecular weight PS seeds were used, whereas well-defined polymer particles were produced easily by using low molecular weight seeds. The use of 1,1-diphenylethylene as a chain terminator during seed polymerization is proposed in this work as an efficient method to lower molecular weight of PS in seed particles while keeping seed size small. This low molecular weight seed template retained its spherical geometry after swelling and polymerization with different second stage monomers.