苯基膦酸改性环氧树脂固化物的制备及其阻燃性能

Preparation and flame-retardant properties of cured epoxy resin modified by phenylphosphonic acid

以苯基膦酸(PPA)和双酚A型环氧树脂(EP)为原料,在无溶剂条件下反应制备了一种含磷的环氧树脂(EP-PPA),并采用傅里叶红外光谱(FTIR)、核磁共振(氢谱、碳谱和磷谱)分析了EP-PPA的结构。依据EP-PPA的环氧值添加预定质量的固化剂4,4'-二氨基二苯甲烷(DDM),采用传统固化方法制备了阻燃性能良好的EP-PPA固化物。采用极限氧指数(LOI)、水平垂直燃烧(UL-94)和锥形量热(Cone)试验分析了阻燃EP-PPA固化物的阻燃性能,并利用热失重技术分析了EP-PPA固化物的热降解过程。研究结果表明,当阻燃剂PPA质量分数为10.6%时,阻燃EP-PPA固化物的LOI与纯EP固化物相比提高了30.5%,能通过UL 94 V-0级,热释放速率峰值(PHRR)、热释放量(THR)以及总烟量(TSP)分别降低了60.3%、22.8%和14.5%,火灾增长指数(FIG)降低了67.0%,火灾性能指数(FPI)提高了62.5%。

A phosphorus-containing epoxy resin(EP-PPA)was prepared by the reaction of phenylphosphonic acid(PPA)and bisphenol A epoxy resin(EP)under solvent-free conditions.Fourier infrared spectroscopy(FTIR)and nuclear magnetic resonance(hydrogen spectrum,carbon spectrum and phosphorus spectrum)were adopted to analyze the structure of EP-PPA.According to the epoxy value of EP-PPA,a calculated amount of curing agent 4,4'-diaminodiphenylmethane(DDM)was added,and a cured EP-PPA with good flame retardant properties was prepared by traditional curing method.Limit oxygen index(LOI),horizontal and vertical combustion(UL-94)and cone calorimetry tests were used to analyze the flame retardant properties of EP-PPA thermosets,and the thermal gravity analysis was used to analyze the EP-PPA thermosets thermal degradation process.The experimental results show that compared with the pure EP thermosets,when the flame retardant PPA content is 10.6%,the LOI of the flame retardant EP-PPA thermosets is increased by 30.5%,making the UL 94 V-0 level passable.The peak heat release rate(PHRR),heat release(THR)and total smoke(TSP)were reduced by 60.3%,22.8%and 14.5%,respectively.The fire growth index(FIG)was reduced by 67.0%,and the fire performance index(FPI)was increased 62.5%.