A Comparative Study on Emulsion Polymerization Processes of Styrene Initiated by Water-soluble and Oil-soluble Initiators  

作　　者：Xiao-Jing Liu Yu-He Tian Yang-Cheng Lu 

机构地区：[1]State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University

出　　处：《Chinese Journal of Polymer Science》2019年第2期142-148,共7页高分子科学（英文版）

基　　金：the financial support of the National Natural Science Foundation of China(Nos.21422603 and U1662120)

摘　　要：The solubility of initiator determines its distribution and the roles played in emulsion polymerization as well as the final products, but this is still lack of systematic investigation. The present work focuses on this issue by comparing the kinetic behaviors and product properties of styrene emulsion polymerization initiated by 2,2-azoisobutyronitrile(AIBN) and potassium persulphate(KPS).Compared to KPS-initiated emulsion polymerization, the AIBN-initiated polymerization was found to be insensitive to the type of emulsifier, and have high polymerization rate as well as narrow molecular weight distribution and particle size distribution. This result indicates the effective free radicals are generated in micelles or colloids, which could decrease the proportion of homogeneous nucleation and make the process and product more controllable. As a consequence, there is a linear relationship between molecular weight of product and AIBN concentration in lg-lg coordinate. It provided a reference for the preparation of latexes with specified molecular weight and supported the possibility of the coexistence of multiple free radicals in one micelle or colloid when using oil-soluble initiator.The solubility of initiator determines its distribution and the roles played in emulsion polymerization as well as the final products, but this is still lack of systematic investigation. The present work focuses on this issue by comparing the kinetic behaviors and product properties of styrene emulsion polymerization initiated by 2,2-azoisobutyronitrile(AIBN) and potassium persulphate(KPS).Compared to KPS-initiated emulsion polymerization, the AIBN-initiated polymerization was found to be insensitive to the type of emulsifier, and have high polymerization rate as well as narrow molecular weight distribution and particle size distribution. This result indicates the effective free radicals are generated in micelles or colloids, which could decrease the proportion of homogeneous nucleation and make the process and product more controllable. As a consequence, there is a linear relationship between molecular weight of product and AIBN concentration in lg-lg coordinate. It provided a reference for the preparation of latexes with specified molecular weight and supported the possibility of the coexistence of multiple free radicals in one micelle or colloid when using oil-soluble initiator.

关 键 词：EMULSION polymerization OIL-SOLUBLE INITIATOR WATER-SOLUBLE INITIATOR STYRENE Reaction mechanism 

分 类 号：O6[理学—化学]