阻燃剂三甲基硅酸笼状硫代PEPA酯的合成与应用

摘要

A new flame retardant,trimethyl silicate-1-thiophospha-2,6,7-trioxabicyclo [2.2.2] octyl-4-methyl ester (TMSSPE),was synthesized by the reaction of trimethyl chlorosilane(TMCS) with 1-thiophospha-4-hydroxymethyl-2,6,7-trioxabicyclo[2.2.2] octane (SPEPA).The effects of solvent,reaction temperature,reaction time and molar ratio on the yield were investigated extensively.The structure and flame retardant properties of the obtained product were characterized by means of Fourier-transform infrared spectroscopy,1H-nuclear magnetic resonance spectroscopy,thermogravimetric analysis and limiting oxygen index.The results indicated that the yield reached 93.2 ％ when the optimal synthetic conditions were set to a n(SPEPA:TMCS) =1.2,a reaction temperature of 45 ℃ and a reaction period of 9 h as well as using dioxane as a solvent.The reactant flame retardant achieved a good thermal stability and the char yield was 25 ％ at 700 ℃,the limiting oxygen index of PP was 27 ％ at a content of 20 wt ％ when being applied for polypropylene (PP).In addition,when this flame retardant was complexed with melamine pyrophosphate or melamine cyanurate,it can generate a high Synergistic flame-retardant efficiency for PP.%以三甲基氯硅烷(TMCS)和1-硫基磷杂-4-羟甲基-2,6,7-三氧杂双环[2.2.2]辛烷(SPEPA)为原料,合成了一种新型阻燃剂三甲基硅酸-1-硫基磷杂-2,6,7-三氧杂双环[2.2.2]辛基-4-甲酯(TMSSPE);探讨了溶剂、反应温度、反应时间及物料摩尔比(n)等对产物产率的影响;通过傅里叶变换红外光谱仪、核磁共振氢谱仪、热失重分析仪及极限氧指数测试等对产物的结构及性能进行了表征.结果表明,TMSSPE的最佳合成工艺条件为:以二氧六环为溶剂,n(SPEPA:TMCS)=1.2,在45℃下反应9h,产率为93.2％;产物具有良好的热稳定性,700℃时的残炭率为25％;其单独应用于阻燃聚丙烯(PP)时,添加20％(质量分数,下同)即可使PP的极限氧指数达到27％,同时其与三聚氰胺聚磷酸盐(MPP)或三聚氰胺氰脲酸盐(MCA)复配用于阻燃PP时,也表现出很好的协同增效作用.