微米级单分散共聚物微球的制备

用分散聚合法制备了苯乙烯 甲基丙烯酸甲酯微米级单分散共聚物微球 ,粒径为 5 4 μm .将分散聚合体系与乳液聚合体系进行了比较 ,并对共聚物微球的形貌、粒径分布及共聚情况进行了表征研究 .

PREPARATION OF MONODISPERSE COPOLYMER MICROSPHERES WITH MICRON SIZE

The size,monodispersity and surface properties of polymer microspheres are especially important in biomedical field,information industry and microelectronics applications.The aim of the study is to obtain monodisperse microspheres carrying functional group in the micron size range by copolymerization.In this study,monodisperse St MMA copolymer microspheres with a diameter of 5 4 μm were prepared by dispersion polymerization in absolute ethanol media using polyvinylpyrrolidone K\|30(PVP) as a steric stabilizer and 2,2′ azobisizobutyronitrile (AIBN) as an initiator.The comparison of dispersion polymerization and emulsion polymerization indicated that their reaction mechanism were different.The copolymer microspheres prepared by emulsion polymerization were in the size range of 0 1～0 5 μm and the size distribution was broad.The kind of copolymer microspheres can coagulate easily and disperse hardly because of the residual emulsifer.The copolymer microspheres prepared by dispersion polymerization were spherical,monodisperse and were able to disperse easily.The statistical results showed that the size distribution of copolymer microspheres conform to normal distribution.The average size was 5 4 μm.The standard deviation( δ ) was 0 16 and the dispersion parameter ( ε ) was 0 02.The SEM photographs showed that the copolymer microspheres had smooth surface and good sphericity.The FTIR results showed that the functional group(MMA) had been successfully incorporated onto the microspheres by copolymerization.