填充聚合物分解热效应对锥形量热法测热结果的影响

研究了应用锥形量热仪测量填充聚合物复合材料燃烧的热释放速率时。填料的分解热效应对测量结果的影响．结果表明，若不对锥形量热仪所测得的结果进行校正，则对强分解吸热的填料，测量结果偏高．定量研究表明，对氢氧化铝和氢氧化镁填料，当氢氧化铝填料的质量分率为80％时．基于PP、PM．MA和PVC的复合材料的燃烧热分别减少了11．1％、19．3％和29．2％；当氢氧化镁填料的质量分率达到80％时。基于PP、PMMA和PVC的复合材料的燃烧热分别减少了13．2％、22．9％和34．7％．在此情况下．测量结果存在很大误差．并且其具体值还因聚合物而异．文中在定量研究的基础上．提出了一种利用分解焓对锥形量热仪测定的有效燃烧热值进行校正的方法。并给出了校正后的结果同原实验值的比较。

EFFECTS OF DECOMPOSITION HEAT ON HEAT RELEASE MEASUREMENT OF FILLER-POLYMER COMPOSITES BY CONE CALORIMETER

Effects of the heat absorbed during decomposition of some flame retardant fillers on the heat release rate measurement of filled polymers using the cone calorimeter have been studied. It shows that endothermic effect of the filler decomposition affects the heat release rate measured by the cone calorimeter, especially at higher levels of loadings. Some typical fillers were studied quantitatively, including alumina trihydrate (ATH) and magnesium hydroxide. For the two fillers, at the loading levels over 70% in polymers, high overestimation is produced, depending on the individual polymer used. A correction procedure was proposed to correct the heat release rate measurement using the cone calorimeter by modifying the effective heat of combustion of the composites using the pyrolysis enthalpy of the fillers. The correction and comparison with the experimental values measured by the cone calorimeter for ATH were presented in the paper.