超声波辅助醋酸乙烯乳液聚合的动力学及机理

Dynamics and Mechanism of Ultrasonic-Assisted Emulsion Polymerization of Vinyl Acetate

针对目前醋酸乙烯聚合中反应速率及单体转化率较低的问题,以过硫酸钾为引发剂、十二烷基硫酸钠为乳化剂,采用预乳化间歇聚合工艺,研究了超声波功率、引发剂用量、乳化剂用量、单体用量、反应温度等因素对超声波辅助醋酸乙烯乳液聚合反应速率的影响,并对超声波辅助乳液聚合的机理进行了探讨,分析了超声波影响聚合的途径.结果表明,在实验范围内,外加超声波可以提高聚合反应速率和单体转化率,聚合反应的表观活化能达51.55 kJ/mol.

In order to improve the reaction rate and monomer conversion of the polymerization of vinyl acetate, potassium persulfate and sodium dodeeyl sulfate were used respectively as the initiator and the emulsifier to produce poly-vinyl acetate by means of pre-emulsifieation intermittent polymerization. The effects of ultrasonic power, initiator dosage, emulsifier dosage, monomer dosage and reaction temperature on the reaction rate of the ultrasonic-assisted emulsion polymerization were then studied. Furthermore, the mechanism of the ultrasonic-assisted emulsion-polymerization was discussed, and the approaches of ultrasonic to affect the polymerization were analyzed. The results show that, in the experimental conditions of the present study, ultrasonic radiation helps to improve the polymeriza. tion rate and the monomer conversion, and may result in an apparent activation energy of 51.55 kJ/mol.