环氧磷酸改性丙烯酸树脂的制备及其阻燃性能研究

Preparation and flame-retardancy performance of poly-acrylate resins modified by epoxy phosphoric acid

利用双酚A环氧树脂E-51与磷酸制备环氧磷酸(EPPA),通过溶液聚合法制备EPPA改性丙烯酸树脂,并研究环氧磷酸用量对溶液聚合单体转化率的影响。采用红外光谱(FTIR)分析EPPA改性丙烯酸树脂的化学组成;通过热重分析(TGA)、极限氧指数(LOI)和UL-94方法测试EPPA改性丙烯酸树脂的热稳定性和阻燃性能,并利用扫描电镜(SEM)和能谱仪(EDS)观察并测试EPPA改性丙烯酸树脂的残炭微观形貌及元素组成。实验结果表明:随着改性树脂体系中EPPA用量的提高,聚合体系单体转化率逐渐下降,改性丙烯酸树脂的阻燃性逐渐提高。当EPPA的用量为w=30.0%时,改性树脂的LOI值可以达到26.7%,并能通过UL-94测试的V-0级别,700℃的成炭率可达w=24.8%,SEM和EDS对树脂残炭的微观形貌与元素组成分析证明磷元素在改性丙烯酸树脂体系中主要起到凝聚相阻燃作用。

Epoxy phosphoric acid(EPPA)was synthesized with bisphenol epoxy resin E-51 and phosphorus acid,which was used to prepare EPPA modified poly-acrylate resins via solution polymerization,and the effects of EPPA dosage on monomer conversion was investigated.The chemical structure of the prepared poly-acrylate resin was characterized by FTIR(Fourier transform infrared spectroscopy),and the thermal stability and flame retardancy of the prepared poly-acrylate resin were measured by TGA(thermal gravimetric analysis),LOI(limited oxygen index)and UL-94 tests.The micro-morphology and element composition of char residues from the EPPA modified poly-acrylate resin were observed by SEM(scanning electron microscope)and EDS(energy dispersive spectrometer).The results show that monomer conversion decreases and flame retardancy increases when the EPPA dosage increases.When the EPPA dosage is w=30.0%,the LOI of EPPA modified poly-acrylate resin is 26.7%,its char yield is 24.8%at 700℃and the resin can pass V-0 level of the UL-94 test.SEM and EDS results indicate that phosphorous shows a condensed-phase flame retardant effect.