磷-氮阻燃固化剂的合成及对环氧树脂性能影响

Synthesis of Phosphorus-Nitrogen Flame Retardant Curing Agent and Its Effect on the Performance of Epoxy Resin

摘要:

以苯膦酰二氯(PPDC)和间苯二甲胺(MXDA)为原料，合成了一种磷-氮阻燃固化剂苯基膦酰二间苯二甲胺(PPMXD)。通过FTIR、1HNMR、ESI-MS、TGA和DSC对该化合物的结构和热性能进行了表征。考察了原料物质的量比、溶剂种类及配比、反应温度、反应时间对PPMXD产率的影响。结果表明，PPMXD的最佳合成条件为：反应温度为20℃，反应时间为7h，n(PPDC):n(MXDA)=1:3.5，采用N,N二甲基甲酰胺与二氯甲烷的混合液作为溶剂，其中m(N,N二甲基甲酰胺)：m(二氯甲烷)=1：2.3，m(溶剂)：m(PPDC)=12：1。将PPMXD应用于环氧树脂固化及阻燃，用TGA、SEM对复合材料的热性能及残炭结构进行了表征，使用氧指数分析仪，垂直燃烧测试仪对试样进行了燃烧测试。结果表明：当w(PPMXD)=28.5%，EP2的极限氧指数达到29%，可通过UL-94 V-0测试，拉伸强度和冲击强度分别达到42.89MPa和6.45KJ/m2。TGA结果显示PPMXD的加入使EP2最大热失重速率由纯EP的18.23%/min降低到了13.98%/min，800℃时的残炭量由16.12%提高到18.86%，SEM结果表明环氧树脂燃烧后残炭表面粗糙，发泡明显，整体表现出了良好的阻燃性能性。

Abstract:

A phosphorus-nitrogen flame retardant curing agent phenyl phosphonic m-Xylylene diamine diamide(PPMXD) was synthesized by phenylphosphonic dichloride(PPDC) and m-Xylylenediamine (MXDA), The chemical structure of the obtained compound was identified by FT-IR、1HNMR、ESI-MS. The thermal stability of PPMXD was tested by DSC and TG. The effects of mole ratio of reactants, reaction temperature and time, the solvent dosage and the type of solvent were investigated． The experimental results demonstrated that the yield of PPMXD was maximum when the reaction temperature was 20℃, the reaction time was 7h, n(PPDC):n(MXDA)=1:3.5, methylene chloride and N,N dimethylformamide was used to be mixed solvent which quantity ratio of methylene chloride to N,N dimethylformamide was 2.3:1, m(solvent)：m(PPDC)=12：1. The PPMXD was used in epoxy, TGA and SEM would study the thermal properties and the epoxy resin carbon residue morphology. The flame retardant properties of epoxy resin were tested by limiting oxygen index (LOI) and vertical experimental characterization of the combustion. When the addition of PPMXD was 28.5%, it could through the UL-94 V-0 test, the oxygen index could reach 29%, the tensile strength and impact strength could reach 42.89MPa and 6.45KJ/m2, respectively. The results of TGA showed that compare with EP, the addition of PPMXD could make the largest thermal decomposition rate of EP2 decrease from 18.93%/min to 13.28%/min, at the same time, the amount of residual carbon at 800℃ also increased from 16.12% to 18.86%. The SEM results show that the surface of the epoxy resin after buring was rough and foamed obvious, which performed good flame retardancy.