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Eri Yoshida 《Colloid and polymer science》2008,286(12):1435-1442
The novel synthesis of polyhedral particles was attained by the dispersion polymerization of styrene in supercritical carbon
dioxide using a polydimethylsiloxane-based macroazoinitiator as a precursor of the surfactant. The macroazoinitiator, VPS-1001,
composed of poly(dimethylsiloxane) and 6-8 molecules of the azo groups served as a precursor of the surfactant for the dispersion
polymerization by azobisisobutylonitrile as an initiator to produce 0.8-4 μm polyhedral particles. The size of the particles
decreased as a result of increasing the VPS-1001 concentration. Too high a concentration of VPS-1001 caused coagulation of
the particles. A decrease in the temperature increased the particle size and size distribution, while a decrease in the pressure
produced particles with nonspecific shapes. An increase in the stirring rotation speed tended to increase the size and size
distribution. However, too high a speed of rotation also caused coagulation of the particles. 相似文献
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Eri Yoshida 《Colloid and polymer science》2008,286(3):351-355
The synthesis of polystyrene microspheres was achieved by the dispersion polymerization of styrene in supercritical carbon
dioxide using azobisisobutylonitrile (AIBN) and a poly(dimethylsiloxane) (PDMS)-based macroazoinitiator, VPS-1001. VPS-1001
contained seven to nine molecules of the azo groups and the PDMS blocks with a molecular weight of 10,000 per molecule. The
polymerization in the presence of both VPS-1001 and AIBN produced polystyrene microspheres with a diameter below 4 μm in over
85% yields, whereas the polymerization with VPS-1001 in the absence of AIBN provided a nonspecific polystyrene in only 20%
yield. The particle size decreased as a result of increasing the concentration of VPS-1001. It was confirmed that the polystyrene
particles were stabilized by the PDMS-block-polystyrene formed through the polymerization initiated by VPS-1001 because the polymerization using a PDMS homopolymer provided
nonspecific polystyrene as a precipitate during the polymerization. 相似文献
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