醋酸乙烯酯种子乳液聚合动力学研究

Kinetic Study of Seeded Emulsion Polymerization of Vinyl Acetate

用装有红外跟踪器和计算机记录监控系统的膨胀计进行了醋酸乙烯酯的种子乳液聚合．聚合直接从乳液聚合的阶段II开始，避开了复杂的成核阶段和成核阶段粒度变化对动力学参数的影响．在引发剂浓度5．030×10－5～1．002×10－3mol／L范围内，依据转化率随时间的变化关系，求出了准稳态聚合速率、自由基进入乳胶粒子的速率、自由基从乳胶粒子解吸的速率和kpn。结果表明：聚合速率、自由基进入乳胶粒子的速率和kpn与引发剂浓度、kpn与聚合速率呈线性关系，

A series of seeded emulsion polymerization of vinyl acetate have been carried out using a dilatometer with a infrared monitor and a computer recording system in the initiator concentration range from 5.030×10-5mol/L to 1.002×10-3mol/L. Due to the polymeriza-tion started from the interval II, the effect of the particle growth on the rate parameters has been avoided. Based on the experiment data of conversion vs time, we got the polymerization rate in quasi-steady state, and then calculated the entry rate coefficient ρ, exit rate coeffi-cient k and kpn. The results showed that the polymerization rate, ρ, k and kpn increased lin-early with increasing initiator concentration. Also, kpn is linear to the polymerization rate.