Fabrication of an epoxy resin and cyanate ester copolymer containing a multifunctional flame retardant with good flame retardancy and low dielectric performance

In this study, a multifunctional flame retardant (DTF) was prepared by reacting DOPO, bis (trifluoromethyl) phenylboronic acid and 1,3,5-tris (oxiran-2-ylmethyl)-1,3,5-triazinane-2,4,6-trione. EPCE/DTF composites were fabricated by incorporating DTF into a copolymer (EPCE) composed of cyanate ester resin and epoxy resin and were subjected to a comprehensive assessment covering mechanical properties, dielectric performance, flame retardancy, and thermal behavior. The results indicated that the introduction of 10 wt.% DTF into EPCE (EPCE/10DTF) raised the limiting oxygen index to 28.6 vol.% and a UL-94 V-0 rating. Moreover, EPCE/10DTF revealed decreases of 20.9% in the heat release rate and 27.5% in the peak heat release rate, respectively, in contrast to EPCE. Furthermore, EPCE/10DTF had a dielectric loss of 0.00852 and a dielectric constant of 3.76 at 10 MHz, respectively. The thermal decomposition process and mechanical performance of EPCE/DTF were also investigated.