埃洛石复配2-羧乙基苯基次膦酸对环氧树脂阻燃及力学性能的影响

将埃洛石纳米管(HNTs)与2-羧乙基苯基次磷酸(CEPPA)复配并用于环氧树脂(EP)阻燃改性,制备了CEPPA-HNTs/EP复合材料。研究了HNTs与CEPPA的配比对CEPPA-HNTs/EP复合材料热稳定性、阻燃性及力学性能的影响。TG分析表明,CEPPA与HNTs复配可提高CEPPA-HNTs/EP复合材料的热稳定性,促进成炭并降低分解速率。锥形量热和极限氧指数分析表明,加入HNTs可降低EP热释放速率,而CEPPA对提高EP的极限氧指数作用更显著。残炭的红外分析及SEM结果表明,燃烧过程中CEPPA与HNTs反应生成硅铝磷酸盐促进凝聚相的脱水交联,形成更致密的炭层。力学性能分析表明,当HNTs与EP和CEPPA与EP的质量比分别为6%和4%时,CEPPA-HNTs/EP复合材料的拉伸强度和冲击强度分别提高了19.4%和17.3%,冲击断面的SEM图像显示CEPPA-HNTs/EP复合材料呈韧性断裂。

Effects of halloysite nanotubes and 2-carboxyethyl phenylphosphonic acid on flame retardant and mechanical properties of epoxy resin

Halloysite nanotubes(HNTs)were compounded with 2-carboxyethyl phenylphosphonic acid(CEPPA)and used for modification of epoxy(EP)to prepare CEPPA-HNTs/EP composite.The effects of the ratios of CEPPA and HNTs on the thermal stability,flame retardancy and mechanical properties of the CEPPA-HNTs/EP composite were studied.TG analysis shows that the combination of CEPPA and HNTs can improve the thermal stability of the CEPPA-HNTs/EP composites,promote the carbonization and reduce the decomposition rate.The analyses of cone and limiting oxygen index show that adding HNTs can reduce the heat release rate,while CEPPA has a more significant effect on the increasing of oxygen index.The FTIR and SEM of the carbon residue show that the reaction of CEPPA and HNTs during the combustion produce silica-aluminate,which promotes the dehydration and crosslinking of the condensed phase.The analysis of mechanical properties shows that when mass ratio of HNTs to EP is6%,mass ratio of CEPPA to EP is 4%,the tensile strength and impact strength of CEPPA-HNTs/EP composite are increased by 19.4%and 17.3%,respectively.SEM morphologies of impact sections of CEPPA-HNTs/EP composite show the characteristics of ductile fracture.