摘要
用钴 60γ射线引发醋酸乙烯酯的分散聚合 ,通过选择各种极性溶剂体系 ,确立了醋酸乙烯酯在极性介质中稳定的分散聚合体系 .对异丙醇 水体系 ,聚合物分子量随剂量率的降低、稳定剂含量的增加、单体浓度的增大、反应温度的升高以及醇水比的降低而增加 .运用XPS、元素分析等表征聚合物粒子 ,及通过辐射接枝理论的分析 。
The dispersion polymerization of VAc initiated by gamma ray irradiation was carried out in polar media using poly (N-vinylpyrrolidone) as a steric stabilizer at room temperature. This method takes advantages of the specialities of radiation induction, and highly uniform polymer microspheres were obtained. The molecular weight of the polymer increased with the increase of stabilizer content and polymerization temperature, and the decrease of absorbed dose rate, monomer concentration, and ratio of alcohol/water. Based on the experimental results (XPS and element analysis), only the physical adsorption of stabilizer was found in the polymer particles. Compared with other monomers, vinyl acetate may not be inclined to graft-copolymerize with poly( N-vinylpyrrolidone) in radiation polymerization systems. This is maybe due to the low activity of VAc grafting with the stabilizer according to the theory of radiation grafting.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2003年第5期718-723,共6页
Acta Polymerica Sinica
基金
安徽省自然科学基金 (批准号 0 3 0 44 80 3 )
中国科技大学青年基金 (KB 3 0 15 )资助项目
关键词
极性介质
醋酸乙烯酯
辐照
引发剂
分散聚合
分子量
稳定机理
radiation-induced
dispersion polymerization
vinyl acetate
molecular weight
stabilization mechanisms
