ZnO与Al(OH)_3在阻燃软PVC中的协同阻燃消烟作用

ZnO and Al(OH)_3 as Flame Retardants and Smoke Suppressants for Flexible Poly (vinyl chloride)

研究了ZnO和Al(OH)3复合阻燃剂对软PVC的协同阻燃消烟作用。通过热分析的方法研 究了阻燃处理后的软PVC从室温到800℃的热降解过程,用Kissinger方程给出了热降解反应的活化能,通过剩炭率的测定以及用电子扫描显微镜(SEM)对燃烧后所生成炭层的观察探讨了协同体系阻燃抑烟的机理。结果表明:经阻燃处理的样品具有较高的极限氧指数(LOI)、剩炭率较低的烟密度等级(SDR)和最大烟密度(MSD),与未处理的样品相比具有较好的阻燃和消烟性能。加入适量的ZnOAl(OH)3复合使用可明显地提高软PVC的LOI和剩炭率,降低材料的SDR和MSD。ZnO的加入可改变PVC的热降解过程,使起始降解温度降低并且使反应的活化能增大,可能属于固相Lewis酸催化机理。

The flame retardants ZnO and Al(OH)_3 as flame retardants and smoke suppressants for flexible poly (vinyl chloride) were studied. The thermal degradations in air of flexible PVC treated with flame retardants ZnO and Al(OH)_3 were studied by differential thermal analysis and thermogravimetry from ambient temperature to 800℃.The kinetic parameters were obtained using the equation of Kissinger.Their mechanisms were studied through the char yield test,SEM,quantitative analysis,thermogravity (TG) and differential thermal analysis (DTA).The results showed that flexible PVC treated with flame-retardants showed a high limiting oxygen index,char yield and a low smoke density rating,maximum smoke density,which indicated that the flame retardance of the treated PVC was improved. Al(OH)_3 combined with a little of ZnO increased the LOI and char yield,decreased SDR and MSD especially. ZnO changed the thermal degradation of PVC,deceased the degradation temperature of PVC and increased the activation energy of the sample,might acted in condensed phases as a Lewis acid.