MTMP熔融态光聚合反应动力学研究

以可聚合型受阻胺哌啶醇衍生物 4- (甲基丙烯酰氧基 ) - 2 ,2 ,6,6-四甲基哌啶醇酯( MTMP)作为单体 ,利用光差动热分析法 ( DPC)系统地研究了 MTMP的光聚合反应活性和反应动力学规律 .结果表明 :反应条件如光引发剂的种类及浓度、聚合温度、气氛和辐照光强等对 MTMP光聚合动力学有显著的影响 ;在反应初期 MTMP光聚合速率同引发剂浓度和辐照光强的平方根成正比 ,这一规律与光引发自由基聚合的动力学理论相吻合 ;利用稳态法和非稳态相结合的方法测定了光聚合过程的动力学常数 ( kp 和 kt) .随着转化率的增加 ,MTMP的链增长速率 ( kp)和链终止速率 ( kt)均呈现增加态势 ,但 kp 增加的幅度大于 kt

Studies on the Reaction Kinetics of Photo-Polymerization for MTMP in Melting State

In this paper,4 methacryloyl 2,2,6,6 tetramethyl piperidine(MTMP)was synthesized.By using Photo DSC technique,the reactivity and the reaction kinetics of photo induced polymerization of MTMP were systematically studied.Results obtained have showed that the photo induced polymerization of MTMP is significantly influenced by such reaction conditions as the type and concentration of photoinitiator,polymerization temperature,ambient environment as well as irradiancy,and that the rate of photopolymerization of MTMP is directly proportional to the square root of photoinitiator concentration(PI] 0 5 ) and incident light intensity(I 0 0 5 ),which is in accordance with the theoretical expectation.The kinetic parameters( k p and k t )of the bulk photopolymerization of MTMP have been determined by Photo DSC.The rate of propagation constant k p and the rate of termination constant k t have been found to be increased with the increase of MTMP conversion,but is much larger than k p .