Effect of stirring rate on particle formation in emulsifier-free, organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene

被引：0
作者：
Hirotaka Moribe
Yukiya Kitayama
Toyoko Suzuki
Masayoshi Okubo
机构：
[1] Graduate School of Engineering,Department of Chemical Science and Engineering
[2] Kobe University,undefined
来源：
Polymer Journal | 2012年 / 44卷
关键词：
controlled/living radical polymerization; emulsion polymerization; particle; organotellurium-mediated living radical polymerization (TERP); self-assembly; stirring; styrene;
D O I：
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学科分类号：
摘要：
Particle formation during the initial stages of emulsifier-free organotellurium-mediated living radical emulsion polymerization (emulsion TERP) of styrene at 60°C was investigated at two stirring rates (220 and 1000 r.p.m.), in which the styrene phase floated as a layer on an aqueous phase at 220 r.p.m. or became dispersed as droplets at 1000 r.p.m. A water-soluble TERP agent, poly(methacrylic acid) (PMAA)-methyltellanyl (PMAA30-TeMe) and a water-soluble thermal initiator, 4,4′-azobis(4-cyanovaleric acid), at alkaline pH were used. The control/livingness was better at 1000 r.p.m. than at 220 r.p.m., and the particle size distribution was also affected by the stirring rate: both nanometer-sized and submicrometer-sized particles were observed at 220 r.p.m., and mainly nanometer-sized particles were observed at 1000 r.p.m. Because the percentage of PMAA30-TeMe consumed in the initial stage was much higher at 1000 r.p.m. than at 220 r.p.m., self-assembly nucleation preferentially occurred at 1000 r.p.m., resulting in nanometer-sized particles and good control/livingness. Stirring at 1000 r.p.m. only in the initial stage of the emulsion TERP followed by 220 r.p.m. induced good control/livingness and the formation of mainly nanometer-sized particles. It is concluded that a high stirring rate in the initial stage is important for the emulsion TERP of styrene to obtain good control/livingness and to control the particle formation mechanism.
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页码：205 / 210
页数：5
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