聚丙烯固相接枝丙烯酸聚合动力学及其接枝聚合速率模型

GRAFTING KINETICS AND GRAFT POLYMERIZATION RATE MODEL OF SOLID PHASE GRAFTING OF ACRYLIC ACID ON POLYPROPYLENE

基于自由基固相接枝聚合的终止反应主要是自由基单基终止反应的假设提出了相应的聚合机理 ,并建立了聚合速率模型 ,聚合速率与引发剂浓度呈 1次方、与单体浓度呈小于 1次方关系 ,与聚合温度服从Arrhenius关系 .实验考察了聚丙烯固相接枝丙烯酸体系聚合温度、引发剂浓度、单体浓度与初始接枝聚合速率的依赖关系 ,这一关系与上述速率模型十分吻合 .采用无约束非线性优化方法得到了各参数的全局最优解 :频率因子为6 86 8× 10 9,表观活化能为 5 8 89kJ·mol-1,单体浓度的幂为 0 78.

Based on the assumption that single radical termination is the main way of termination reaction of free radical solid phase graft polymerization, the graft polymerization mechanism and the graft polymerization rate model were proposed. The expression of grafting rate model is Rp,g=Aexp (-Ea/RT) [I][M]α. The rate of graft polymerization was found to depend on initiator and monomer concentration to the 1st and less thank order respectively, and the actual rate constant of graft polymerization was found to obey the Arrhenius law. The effects of graft polymerization temperature and the concentration of initiator and monomer on the initial rate graft polymerization were investigated in experiments. The relationship between initial rate of graft polymerization and the factors mentioned above coincided with the grafting rate model quite well. The parameters of the model were obtained by the nonconstraint-nonlinear optimization method. The frequent factor was 6.868×109, the apparent active energy was 58.89 kJ&middotmol-1 and the exponential order of monomer concentration was 0.78.