摘要
本文根据ESR方法测定的自由基浓度在聚合反应过程中的变化,研究了甲基丙烯酸甲酯以过氧化苯甲酰和二甲基苯胺为引发体系的自由基聚合反应。在反应前期,自由基浓度变化速度远小于引发速度,是一种自由基浓度缓慢变化的假稳态。由死端聚合結果得到引发剂分解速率常数k_d=0.091/mol·min^(-1)(20℃)。引发效率为0.11。由自由基浓度计算了链终止速率常数k_(t0)结果表明:
Using ESR spectrometer, the radical polymerization of methyl methacrylate initiated with dimethyl aniline and benzoyl peroxide was studied. In the initial satge of the polymerization, the variation rate of radical.concentration was very small compared with the initiation rate. The system was kept in a quasi stationary state with a small variation rate of radical concentration. From the so called died end polymerization, we obtained the decomposition rate constant of the initiator kd =0.09 1 mol-1 min-1(20℃). Initiation efficiency was 0.11. Chain termination rate constant kt was calculated with the experiment data of radical concentration R.The results showed that:1/kt = 1/kt0 + Rexp [-7.2 + 16.5[DMA]0(1-φm)] k10 = 4.04×109-(1mol-1 min-1)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
1989年第5期38-44,共7页
Polymer Materials Science & Engineering
