木质素与含磷阻燃剂对环氧树脂固化物阻燃性能的影响

Properties of Co-cured Flame Retardant Epoxy Resin Materials Obtained by Lignin and Phosphorus-containing Flame Retardant

利用不同质量比的木质素、苯酐(PA)、环氧树脂(EP)、2-(二苯基磷酰基)琥珀酸(DPPOSA)共固化制备出一系列环氧树脂固化物,采用极限氧指数测试、UL-94垂直燃烧评级测试、锥形量热仪热释放速率和总热释放量测试、空气条件下的热重分析测试和扫描电镜对环氧固化物进行测试和分析。当EP为90.0%、PA为6.5%、DPPOSA为2.0%、木质素为1.5%时制备的环氧固化物(P-12)的热稳定性能和阻燃性能得到了明显的改善。阻燃性能测试表明:其极限氧指数(LOI)达到34.6%,垂直燃烧测试通过UL-94的V-0级,热释放速率和热释放总量也有效降低;热降解测试结果表明:DPPOSA和木质素的加入可以使材料的降解时间提前,成炭能力增强;扫描电镜结果显示:添加DPPOSA和木质素的环氧固化物燃烧后形成连续、均一、紧密的炭层,进一步证明DPPOSA和木质素的加入使环氧固化物的成炭能力得到增强。

A series of cured epoxy resin thermosets were prepared by co-curing of lignin,phthalic anhydride(PA),epoxy resin(EP)and 2-(diphenylphosphoryl)succinic acid(DPPOSA).The epoxy resin thermosets were studied and analyzed by limiting oxygen index(LOI),vertical burning test,cone calorimeter test(CONE),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).The thermal stability and flame retardancy of epoxy resin thermosets(P-12)were significantly improved when the EP content was 90.0%,the PA content was 6.5%,the DPPOSA content was 2.0%,and the lignin content was 1.5%.The flame retardant performance test showed that its LOI reached 34.6%,and the vertical burning test passed UL-94 V-0 level,and the heat release rate and total heat release were also effectively reduced.The results of TGA tests showed that DPPOSA and lignin could advance the degradation time and enhance char-forming ability.The results of SEM revealed that the epoxy resin thermosets formed a continuous,uniform and tight carbon layer,and it was further proved that the char-forming ability of epoxy cured thermosets were improved with the addition of lignin and DPPOSA.