阻燃剂2-甲基-2-氧代-5-乙基-5-羟甲基-1,3-二氧-2-磷杂环己烷的合成、表征及应用

Synthesis and characterization of 2-methyl-2-oxo-5-ethyl-5-hydroxymethyl-1,3-dioxy-2-phosphoheterocyclic hexane flame retardant

以三羟甲基丙烷和甲基膦酸二甲酯为原料,采用离子液体[Bmim]BF4催化剂催化合成了膦酸酯阻燃剂,通过气相色谱跟踪反应,气相色谱-质谱联用仪(GC-MS)分析最终合成产物,得知产品主要组成为环状膦酸酯2-甲基-2-氧代-5-乙基-5-羟甲基-1,3-二氧-2-磷杂环己烷。对合成产品进行了红外光谱、核磁磷谱结构分析和热稳定性分析。并将合成产品应用于硬质聚氨酯泡沫(RPUF),通过极限氧指数(LOI)和垂直燃烧实验评价了RPUF的阻燃性能。结果表明:离子液体[Bmim]BF4可以高效催化环状膦酸酯合成反应,产物环状膦酸酯主要成分结构明确,热稳定性好,对RPUF有优良的阻燃性能,添加质量为20%时可使RPUF的LOI值从18.5%提高到25.5%,续燃时间由24s降低到0s,残留质量分数从21.8%提高到80.4%。

A cyclic phosphate flame retardant was synthesized from trimethylolpropane and methyl phosphonate dimethyl ester by ionic liquid[Bmim]BF4 catalyst.The reaction was traced by gas chromatography and the final product was analyzed by GC-MS.It was found that the main composition of the product was cyclic phosphonate 2-methyl-2-oxy-5-ethyl-5-hydroxymethyl-1,3-dioxy-2-phosphoheterocyclic hexane.FT-IR,31 PNMR structure analysis and TG/DTG thermal stability analysis were carried out.The synthetic product was applied to rigid polyurethane foam(RPUF)and the flame retardant properties of RPUF were evaluated by LOI and vertical combustion experiments.The results shown that the ionic liquid can catalyze the synthesis of cyclic phosphate esters with high efficiency,the main composition of the product was clear,thermal stability was good and flame retardant performance to RPUF was excellent.When adding20%(w/w),the LOI value of RPUF increased from 18.5%to 25.5%,the afterburning time decreased from 24 sto 0 s,and the PMR value of residual mass fraction increased from 21.8%to 80.4%.