Flame-retardant cyanate ester resin with suppressed toxic volatiles based on environmentally friendly halloysite nanotube/graphene oxide hybrid

摘要

Development of high-performance thermosetting resins by adding environmentally friendly flame retardant to heat-resistant resins without deteriorating their outstanding thermal stability is an important research direction. Here, a unique hybrid (GHNT) consisting of graphene oxide (GO) and halloysite nanotubes (HNT) was synthesized, and then a series of composites based on cyanate ester (CE) resin were fabricated. The effects of GHNT on the heat resistance, flame retardancy, and smoke suppression of GHNT/CE composites were intensively investigated. The GHNT/CE composite with 5.0 wt % GHNT not only has about 15.1 degrees C higher initial degradation temperature, but also shows 54.6% or 37.9% lower peak heat release rate or maximum smoke density than CE resin. These results clearly demonstrate that GHNT is not the simple combination of GO and HNT; instead, it obviously shows positive synergistic effects in simultaneously improving the flame retardancy and thermal resistance of CE resin. The improved flame retardancy could be attributed to condensed-phase mechanisms, including increasing char yield, building a dense char layer, and free radical scavenging. (C) 2018 Wiley Periodicals, Inc.