【摘要】 研究了二氧化锰(MnO2)和氧化铁(Fe2O3)对聚氯乙烯(PVC)热降解和热氧化降解过程的影响。电导率测试得出:PVC在空气和氮气环境下热降解时,都表现出自诱导脱氯化氢反应特征,而MnO2一定程度上消除了PVC热降解时自加速反应特征,Fe2O3实质性地改变了氯化氢释放规律,随时间的推移,使氯化氢释放量缓慢线性增加。热失重法与差热分析量热法显示MnO2和Fe2O3均阻止了氯化氢挥发释放过程,且加速了PVC主链断裂与挥发过程。更多还原

【Abstract】 Thermal degradation of poly(vinyl chloride) in the presence of the additive ferric oxide (Fe2O3) or managanese dioxide (MnO2) was studied with isothermal treatment, electric conductance measurement, thermogravimetry (TG) and differential scanning calorimetry (DSC). The electric conductance measurement results show that poly(vinyl chloride) thermally degrades in the form of autoacceleration both in air and nitrogen, MnO2 modifies the elimination of hydrogen chloride (HCl) by removing autoacceleration to some extent, whereas Fe2O3 causes a slow but steady increased formation of HCl, which is substantially different from that of virgin PVC. TG and DSC indicate that both MnO2 and Fe2O3 delay the weight loss or evaporation of HCl by increasing heat of degradation in the initial degradation, and promote main chain scission and weight loss at later stage.更多还原