氮磷反应型阻燃剂的合成及其阻燃聚氨酯的性能

Synthesis of Reactive Flame Retardant Containing Nitrogen and Phosphorus and Its Flame Retardancy to Polyurethane

以多聚甲醛、二异丙醇胺和亚磷酸二乙酯为原料,通过两步反应合成了反应型阻燃剂N,N-二(2-羟异丙基)氨甲基膦酸二乙酯(HPAPE),采用单因素法得到了合成中间体5-甲基-3-(2-羟异丙基)-1,3-恶唑的最佳条件:反应时间为4 h,反应温度为60℃,多聚甲醛与二异丙醇胺的摩尔比为1.2∶1.0,蒸馏压力为18 kPa;利用正交试验得到了合成阻燃剂HPAPE的最佳条件:温度为50℃,时间为5.0 h,反应物料MHPZ与亚磷酸二乙酯的摩尔比为1.0∶1.1,催化剂强酸性阳离子交换树脂用量为反应物料总质量的0.3%。利用极限氧指数(LOI)、垂直燃烧法测试了HPAPE阻燃聚氨酯(PUR)的性能,采用热重分析研究了HPAPE阻燃PUR的热分解过程及成炭性能,并用Proteus Analysis软件计算了其动力学参数热分解活化能。结果发现,HPAPE质量分数为24%时,HPAPE阻燃PUR的LOI为26.2%,阻燃级别可达UL94 V–0级,说明阻燃剂HPAPE对PUR具有明显的阻燃效果。在700℃时,HPAPE阻燃PUR的质量保持率比PUR高4.91%,动力学参数热分解活化能比PUR提高了32.40 kJ/(mol·K),表明阻燃剂HPAPE对PUR的热降解具有加速成炭的功效。

A reactive flame retardant N, N-bis（2-hydroxyisopropyl）-amin0methyl phosphonic acid diethyl ester（HPAPE）was synthesized via paraformaldehyde, diisopropanolamine, diethyl phosphite by two step reaction. The best reaction conditions of 5-methy-3- （2- hydroxyisopropyl）-1, 3-oxazole（MHPZ） were obtained by the single factor experiment ： the reaction time is 4 h, the reaction temperature is 60 ℃, the mole ratio of paraformaldehyde and diisopropanolamine is 1.2 ： 1.0, the distillation pressure is 18 kPa. The best reaction conditions of HPAPE were found by the orthogonal experiment ： the temperature is 50℃, the time is 5.0 h, the mole ratio of MHPZ and dimethyl phosphite is 1.0 ： 1.1, the mass fraction of catalyst strong acid cation exchange resin in the reactant is 0.3%. The flame retardancy and the thermal degradation behavior of HPAPE flame retardant polyurethane（PUR） were studied by the limiting oxygen index（LOI）, UL94 vertical flame test and the thermogravimetric analysis. The results show that HPAPE mass fraction of 24% are added into PUR to get about 26.2% of the LOI and UL94 V-0 rating, which shows good flame retardancy. Comparing with PUR, the mass residual rate of HPAPE flame retardant PUR at 700℃ increase by 4.91% and the activation energy for the decomposition increase by 32.40 kJ/（mol· K） by calculating of proteus analysis software, which shows that the flame retardants can catalyze decomposition and carbonization of PUR.