一种自交联型阻燃剂的合成及对固态环氧树脂的性能

Synthesis of a self-crosslinking flame retardant and its performance on solid epoxy resin

环氧树脂(EP)凭借其良好的化学稳定性、电气性能、粘接性能及机械强度,广泛地应用于国民生产和生活的各个领域。但其易燃的特性给人们的生命和财产安全带来了威胁,因此,对环氧树脂进行阻燃改性一直是人们的研究热点。以3-氨基酚、4-硝基邻苯二甲腈、4-甲酰苯硼酸及9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为原料,分别通过取代、缩合和加成等反应合成了一种具有自交联能力的阻燃剂(DBPN),并将其用于固态环氧树脂的阻燃,系统研究了环氧树脂复合材料的热稳定性、阻燃性能及阻燃机制。结果表明:添加6.4wt%的DBPN,环氧树脂的初始热分解温度由纯EP的372.6℃提前至351.5℃,这有利于在燃烧过程中提前形成阻隔性炭层,隔绝传质传热过程;其UL-94垂直燃烧测试由N.R提升至V-2级,热释放速率峰值(PHRR)、总热释放量(THR)、烟生成速率峰值(PSPR)和总烟释放量(TSP)则较纯EP分别下降了34.2%、29.5%、20.8%和17.8%;通过对残炭的分析,提出了环氧树脂复合材料的阻燃机制。该工作为新型无卤阻燃剂的制备提供了创新思路。

Epoxy resin(EP)is widely used in various fields of national production and life due to its excellent chemical stability,electrical properties,adhesive properties,and mechanical strength.But its flammable properties pose a threat to people's lives and property safety,thus,the flame retardancy modification of epoxy resin has always been a research hotspot.Using 3-aminophenol,4-nitrophthalonitrile,4-formylphenylboronic acid,and 9,10-dihydro-9-oxa-10-phosphazephenanthroline-10 oxide(DOPO)as raw materials,a self-crosslinking flame retardant(DBPN)was synthesized through substitution,condensation,including addition reactions,and was used for flame retardancy of solid epoxy resin.The thermal stability,flame retardancy,and flame retardancy mechanism of epoxy resin composites were systematically studied.The results show that adding 6.4wt%DBPN advance the initial thermal decomposition temperature of epoxy resin composite from 372.6℃of neat epoxy resin(EP)to 351.5℃,which is conducive to the formation of a carbon layer barrier during the combustion process,isolating the mass and heat transfer processes.Its UL-94 vertical combustion test increased from N.R to V-2 level,with peak heat release rate(PHRR),total heat release(THR),peak smoke production rate(PSPR),and total smoke production(TSP)decreased by 34.2%,29.5%,20.8%,and 17.8%,respectively,compared to neat EP.The flame retardancy mechanism of epoxy resin composites was proposed through the analysis of residual carbon.This work provides innovative ideas for the preparation of new halogen-free flame retardants.