Development of a DOPO‐containing melamine epoxy hardeners and its thermal and flame‐retardant properties of cured products

作者：Yuanqin Xiong, Zhuojuan Jiang, Yanyan Xie, Xuyong Zhang, Weijian Xu · 发表于：Journal of Applied Polymer Science · 年份：2012 · DOI：10.1002/app.37635 · 被引用次数：116 · 研究领域：Flame retardant materials and properties、Epoxy Resin Curing Processes、Synthesis and properties of polymers

Abstract In this study, a novel Schiff base of melamine used as flame‐retardant curing agent for epoxy resins, was synthesized via condensation reaction of 4‐hydroxybenzaldehyde with melamine, followed by the addition of 9,10‐dihydro‐9‐oxa‐10‐phosphaphen‐anthrene 10‐oxide (DOPO) to the resulting imine linkage. The structure of DOPO‐containing melamine Schiff base (P‐MSB) was characterized by Fourier transformed infrared spectroscopy, 1 H‐nuclear magnetic resonance ( 1 H‐NMR) and 31 P‐NMR. The compound (P‐MSB) was used as a reactive flame retardant in o ‐cresol formaldehyde novolac epoxy resin (CNE) to prepare flame‐retardant epoxy resins for electronic application. The thermal and flame‐retardant properties of the epoxy resins cured by various equivalent ratios phenol formaldehyde novolac (PN) and P‐MSB were investigated by the nonisothermal differential scanning calorimetry, the thermogravimetric analysis, and limiting oxygen index test. The obtained results showed that the cured epoxy resins possessed high T g (165°C) and good thermal stability ( T 5% , 321°C). Moreover, the P‐MSB/CNE systems exhibited higher limiting oxygen index (35) and more char was maintained in P‐MSB/CNE systems than that in PN/CNE system and the effective synergism of phosphorus–nitrogen indicated their excellent flame retardancy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013