聚磷酸酯膨胀阻燃剂复配有机蒙脱土阻燃改性环氧树脂

Ammonium Polyphosphate/Organic Montmorillonite Compounds Flame-retardant Epoxy Resin

以间苯二胺为固化剂,聚苯氧基磷酸-2-10-氢-9-氧杂-磷杂菲对苯二酚酯(POPP)、聚磷酸铵(APP)为阻燃剂,复配质量分数为1%有机蒙脱土(OMMT)为膨胀阻燃体系,对环氧树脂(EP)进行阻燃改性。通过极限氧指数测定仪、垂直燃烧测定仪同步热分析仪、锥形量热等研究改性EP的阻燃性能、热性能和力学性能。结果表明,当膨胀阻燃体系(2.5%POPP/APP+1%OMMT)添加量为3.5%时,改性EP可达UL 94V-0级,同时LOI为25.2%;当膨胀阻燃体系添加量为11%时,改性EP的LOI值进一步升高到31.7%;阻燃剂的加入,使EP的初始分解温度略有降低,但残炭量明显增加;POPP/APP/OMMT的加入很大程度上降低了EP的热释放速率、烟释放量和平均热释放速率。

An epoxy resin was modified with an intumescent flame-retardant system(IFR)based on poly(2-10-hydrogen-9-oxa-phosphaphenanthrenehydroquinone phenyl phosphate)(POPP)and ammonium polyphosphate(APP)at a weight ratio of1/2,and then cured with m-phenylenediamine to form flame-retardant thermosets(FR-EP).Organic montmorillonite(OMMT)was incorporated into this IFR to obtain a synergistic flame-retardant and smoke-inhibiting effect at an OMMT content of1.0wt%.The combining effect of IFR and OMMT on epoxy resin was investigated by means of limiting oxygen index(LOI),vertical burning experiment,thermogravimetric analysis,cone calorimetry and scanning electron microscopy.The results indicated that the POPP/APP/OMMT-modified epoxy thermosets achieved a V-0classification in the UL94vertical burning experiment as well as an LOI of25.2vol%.The initial decomposition temperature of the modified epoxy thermosets decreased slightly,but the residual char increased significantly.According to the cone test results,the heat release rate,total heat release and total smoke release all decreased dramatically.Moreover,the combination of POPP,APP and OMMT promoted the formation of a homogeneous and compact char layer on the epoxy thermoset during combustion.In addition,the OMMT was found to enhance the mechanical properties of the epoxy thermosets.