Photoinitiated dispersion polymerization of methyl methacrylate: A quick approach to prepare polymer microspheres with narrow size distribution
Photoinitiated dispersion polymerization of methyl methacrylate: A quick approach to prepare polymer microspheres with narrow size distribution
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甲基丙烯酸甲酯的光引发分散聚合：一种快速制备窄尺寸分布聚合物微球的方法
DOI：
10.1002/pola.22473
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发表时间：
2008-02-15
影响因子：
--
通讯作者：
Chen, Yonglie
中科院分区：
文献类型：
--
作者：
Chen, Jia;Zeng, Zhaohua;Chen, Yonglie
以聚N-乙烯基吡咯烷酮（PVP）为空间位阻稳定剂，Darocur 1173为光引发剂，以乙醇和水为分散介质，进行了甲基丙烯酸甲酯的光引发分散聚合。在室温下紫外光照射30分钟内，转化率达到93.7%，得到的微球数均直径为0.94 μ m，多分散指数（PDI）为1.04。X射线光电子能谱（XPS）分析表明，微球表面只有部分被PVP覆盖。随着PVP稳定剂的浓度从2%增加到15%，粒径从2.34 μ m减小到0.98 μ m。额外的稳定剂（高于15%）对颗粒大小和分布没有影响。增加介质极性或降低单体和光引发剂浓度导致粒径减小。由于光引发分散聚合反应速率高，反应介质对稳定剂的溶剂性影响稳定剂在粒子表面的吸附，对控制粒子的粒径和均匀性至关重要。(C)2008 Wiley Periodicals，Inc.
Photoinitiated dispersion polymerization of methyl methacrylate was carried out in a mixture of ethanol and water as dispersion medium in the presence of poly(N-vinylpyrrolidone) (PVP) as the steric stabilizer and Darocur 1173 as photoinitiator. 93.7% of conversion was achieved within 30 min of UV irradiation at room temperature, and microspheres with 0.94 mu m number-average diameter and 1.04 polydispersity index (PDI) were obtained. X-ray photoelectron spectroscope (XPS) analysis revealed that only parts of surface of the microspheres were covered by PVP. The particle size decreased from 2.34 to 0.98 pm as the concentration of PVP stabilizer increased from 2 to 15%. Extra stabilizer (higher than 15%) has no effect on the particle size and distribution. Increasing medium polarity or decreasing monomer and photoinitiator concentration resulted in a decrease in the particle size. Solvency of reaction medium toward stabilizer, which affects the adsorption of stabilizer on the particle surface, was shown to be crucial for controlling particle size and uniformity because of the high reaction rate in photoinitiated dispersion polymerization. (C) 2008 Wiley Periodicals, Inc.