磷杂菲/环氧树脂复合材料的热分解动力学研究

Thermal decomposition kinetics of phosphaphenanthrene/epoxy composites

近年来,磷杂菲阻燃剂因反应活性高、相容性好而被广泛应用于阻燃环氧树脂(EP)。首先,以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和P2S5为原料,甲苯为溶剂,在氮气保护下合成磷杂菲阻燃剂9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物(DOPS);其次,将其添加到EP中制备磷杂菲/环氧树脂复合材料(DOPS/EP);再次,通过TG/DTG方法研究了DOPS/EP的热分解过程;最后,采用Kissinger法、Flynn-Wall-Ozawa法和Coast-Redfern法对DOPS/EP热分解过程中的非等温热分解动力学数据进行了分析,求出热分解反应的活化能和指前因子,并推测出可能的热分解反应机理及其动力学方程。实验结果表明,DOPS/EP的热分解过程分为两个阶段,其热分解动力学参数分别为EK1(DOPS/EP)=163.82 kJ/mol,lnAK1=35.60,EO1(DOPS/EP)=164.36 kJ/mol,EK2(DOPS/EP)=195.59 kJ/mol,lnAK2=35.67,EO2(DOPS/EP)=196.18 kJ/mol;其两个阶段的机理函数均为g(α)=[-ln(1-α)]4,反应级数n=4,热分解机理均属于随机成核和随后增长反应。

In recent years,phosphaphenanthrene and its derivatives have been widely used in flame retardant epoxy resin(EP)because of their high reactivity and good compatibility in EP.Firstly,the 6H-dibenzo[c,e][1,2]oxaphosphinine-6-sulfide(DOPS)was synthesized through the reaction of DOPO and P2S5.Secondly,phosphaphenanthrene/epoxy composites(DOPS/EP)was prepared by adding DOPS to EP.Thirdly,the thermal decomposition process of DOPS/EP was studied by TG/DTG method.Finally,the thermal decomposition kinetics parameters,including the activation energy and pre-exponential factor,the thermal decomposition kinetics mechanism function and reaction order of the decomposition process were calculated by Kissinger,Flynn-Wall-Ozawa and Coast-Redfern equation.The results show that the thermal decomposition process of DOPS/EP was divided into two stages,and the thermal decomposition kinectic parameters were EK1(DOPS/EP)=163.82 kJ/mol,lnAK1=35.60,EO1(DOPS/EP)=164.36 kJ/mol,EK2(DOPS/EP)=195.59 kJ/mol,lnAK2=35.67,EO2(DOPS/EP)=196.18 kJ/mol.The thermal decomposition kinetic equation of DOPS/EP could be expressed as g(α)=[-ln(1-α)]4,while the reaction order n=4,and the thermal decomposition mechanism was random nucleation and its subsequent growth.