[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

KINETICS OF GRAFTING ACRYLONITRILE ONTO STARCH BY MANGANIC PYROPHOSPHATE INITIATION

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。

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 K0 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: