[Mn(H_2P_2O_7)_3]~(3-)引发淀粉与丙烯腈接枝聚合反应的动力学研究

以Mn(H_2P_2O_7)_3]~(3-)为引发剂,研究了丙烯腈与玉米淀粉的接枝共聚反应。由实验结果求出了反应速率与引发剂浓度、单体浓度、淀粉浓度和反应温度的关系,推导并验证了接枝反应动力学模型,探讨了反应机理,求得了接枝反应活化能。

KINETICS OF GRAFTING ACRYLONITRILE ONTO STARCH BY MANGANIC PYROPHOSPHATE INITIATION

The graft copolymerization of acrylonitrile onto corn starch was investigated using manganic pyrophosphate Mn(H₂P₂O₇)₃]₃- as initiator. The effects of initiator concentration, monomer concentration, starch concentration and temperature on the grafting reaction have been examined. The results obtained are.1. In the range of Mn³⁺] value from 2.0 to 2.5×10^-3mol/L), the grafting reaction was dominantly terminated by polymer radical combinations, the polymerization rate is expressed as:From Arrhenius equation,with least square method K_o was calculated to be 3.37×10²(L/mol·s)and activation energy E to be 25.90(kJ/mol).2. When Mn³⁺]was increased to 3.0×10^-3mol/L,Mn³⁺ion may terminate the grafting reaction and the rate equation is described as.