两种环氧树脂用磷氮阻燃剂的合成与应用研究

将4,4'-二氨基二苯甲烷(DDM)分别与苯甲醛和水杨醛进行缩合反应,所得两种缩合产物分别再与9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)进行加成反应,得到两种新型磷氮阻燃剂A和B,并通过红外吸收光谱(FTIR)、核磁共振(NMR)和质谱(MS)方法证实了产物的结构。结果表明:所得阻燃剂分子可以和DDM一起充当环氧树脂(EP)的固化剂。将阻燃剂A、B分别同DDM加入到EP中,固化后形成的环氧固化物的Tg值和热稳定性有小幅下降,而阻燃性能大幅提高:当环氧固化体系的含磷量为1.0%时,所有环氧固化物垂直燃烧等级均达到UL94 V-0级;当磷含量达到1.5%时,B的环氧固化物的极限氧指数(LOI)达到41.2%。

Study on Synthesis and Application of Two Phosphorus Nitrogen Flame Retardants for Epoxy Resin

Two novel flame retardants A and B were successfully prepared from two steps: condensation reaction between diaminodiphenylmethane(DDM) and benzaldehyde(or 2-hydroxybenzaldehyde);addition reaction between the above condensation compound and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO).The structures of flame retardants A and B were characterized by Fourier transform infrared spectrum(FTIR),nuclear magnetic resonance(NMR) and mass spectrometry(MS) method.The result show that: flame retardants A and B can serve as co-curing agents of diaminodiphenylmethane(DDM) for the curing reaction of epoxy resin(EP).The epoxy thermosets containing DDM and flame retardant A(or B) exhibit moderate changes in glass transition temperature(Tg),thermal stability,and show excellent flame retardancy: UL94 V-0 grade can be obtained when phosphorus content of the epoxy thermoset is only 1.0%,and the limiting oxygen index(LOI) of epoxy resin system containing flame retardant B reaches 41.2% when phosphorus content up to 1.5%.