DOPO基膦酸铝盐的制备及其阻燃环氧树脂的性能研究

以10-羟基-9-氧杂-10-磷杂菲-10-氧化物(DOPO-OH)和六水合氯化铝为原料合成了一种DOPO基膦酸铝盐(DOPO-Al)阻燃剂,通过红外光谱、扫描电镜、能谱、核磁共振磷谱和热失重表征了其结构,并制备了DOPO-Al阻燃的环氧树脂,通过极限氧指数、锥形量热、热失重和差示扫描量热测试分析了该树脂的阻燃和热性能。结果表明,DOPO-Al为高温阻燃剂,其初始热分解温度(T_5%)高达595.5℃。DOPO-Al能提高环氧树脂的阻燃性能和耐热性。当DOPO-Al添加量为7.5%(wt)时,环氧树脂的LOI值由24.1%提高至31.3%;在燃烧过程中,使其热释放速率峰值、平均热释放速率、总热释放、总烟释放和总烟产量均降低,使残留物增加幅度高达135%。炭层分析表明DOPO-Al存在凝聚相阻燃机理。环氧树脂的T_5%和玻璃化转变温度分别高达368.9℃和161.8℃,所制备阻燃环氧树脂具有较好的热性能。

Preparation of DOPO-based Aluminum Phosphinate and Its Flame Retarding Epoxy Resin

DOPO-based aluminum phosphinate,named as DOPO-Al,was synthesized from 10-hydroxy-9-oxa-10-phosphorphenanthrene-10-oxide(DOPO-OH)and aluminum chloride hexahydrate.Its structure was characterized by the infrared spectrum,scanning electron microscope,energy spectrum,phosphorus nuclear magnetic resonance spectrum and thermogravimetry.The flame-retardant epoxy resin based on DOPO-Al was prepared,and it flame-retardant and thermal properties were analyzed using limiting oxygen index(LOI),cone calorimetry,thermogravimetry and differential scanning calorimetry.The results showed that DOPO-Al was a high-temperature flame retardant,and its initial thermal decomposition temperature(T5%)was as high as 595.5℃.The flame-retardant property and heat resistance of epoxy resin were improved by incorporation of DOPO-Al.When 7.5%(wt)DOPO-Al was introduced into the epoxy resin,the LOI value of epoxy resin was increased from 24.1%to 31.3%,and during the combustion,its peak heat release rate,average heat release rate,total heat release,total smoke release and total smoke production were all reduced,and the increase rate of the residue was up to 135%.The analysis of carbon layer suggested that DOPO-Al existed the condensed-phase flame-retardant mechanism.Its T5%and glass transition temperature were up to 368.9℃and 161.8℃,respectively.The prepared flame-retardant epoxy resin had the good thermal properties.