Effects of properties of the surface layer of seed particles on the formation of golf ball-like polymer particles by seeded dispersion polymerization
Effects of properties of the surface layer of seed particles on the formation of golf ball-like polymer particles by seeded dispersion polymerization
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DOI：
10.1038/pj.2009.313
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发表时间：
2010
期刊：
影响因子：
2.8
通讯作者：
Natsumi Konishi;Teruhisa Fujibayashi;T. Tanaka;H. Minami;M. Okubo
中科院分区：
文献类型：
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作者：
Natsumi Konishi;Teruhisa Fujibayashi;T. Tanaka;H. Minami;M. Okubo
在甲醇/水（80/20,w/w）的介质中，用不同壳厚的PS-核/P （S-NaSS）壳种子粒子对甲基丙烯酸正丁酯(PS)/聚苯乙烯-苯乙烯磺酸钠(P (S-NaSS))/聚甲基丙烯酸正丁酯（Pn-BMA）粒子进行种子分散聚合，制备了具有“高尔夫球”形状的微米级单分散聚苯乙烯(PS)/聚苯乙烯-苯乙烯磺酸钠（P (S-NaSS)）粒子，然后将十二烷蒸发。从热力学和动力学的角度研究了种子颗粒的亲水性P （S-NaSS）壳性质对球状颗粒形成的影响。亲水壳较厚的PS/P （S-NaSS）种子粒子表面通过缩小Pn-BMA/十二烷结构域形成的凹痕较深，而亲水壳较薄的PS/P (S-NaSS)/Pn-BMA复合粒子表面呈现多面体形状。这是由于通过降低单体浓度来减少壳层厚度，减少了包含P （S-NaSS）的壳段的分子量，这似乎导致了粒子表面Pn-BMA/十二烷结构域的迁移率增加。在这一发现的基础上，当种子颗粒的壳部分分子量增加时，即使种子颗粒的壳厚度很薄，也会形成高尔夫球状的颗粒。
Micrometer-sized, monodisperse polystyrene (PS)/poly (styrene-co-sodium styrene sulfonate)(P (S-NaSS))/poly (n-butyl methacrylate)(Pn-BMA) composite particles having a ‘golf ball-like’shape were prepared by seeded dispersion polymerization of n-butyl methacrylate with PS-core/P (S-NaSS)-shell seed particles with various shell thicknesses in the presence of dodecane droplets in a methanol/water (80/20, w/w) medium, followed by evaporation of the dodecane. The effects of the hydrophilic P (S-NaSS)-shell properties of seed particles on the formation of golf ball-like particles were investigated on the basis of thermodynamic and kinetic considerations. The dimples at the surface formed by the volume reduction of Pn-BMA/dodecane domains were deep when PS/P (S-NaSS) seed particles, the hydrophilic shell of which was thick, were used, whereas PS/P (S-NaSS)/Pn-BMA composite particles, the P (S-NaSS) hydrophilic shell of which was thin, exhibited a polyhedral shape. This is attributed to the fact that the molecular weight of the shell moiety comprising P (S-NaSS) was reduced by lowering the monomer concentration to decrease shell thickness, which seems to result in an increase in the mobility of Pn-BMA/dodecane domains at the particle surface. On the basis of this finding, when the molecular weight of the shell moiety of the seed particle was increased, golf ball-like particles were formed, even if the shell thickness of seed particles was thin.