Fire-retardant and smoke-suppressant performance of an intumescent waterborne amino-resin fire-retardant coating for wood

Abstract

An intumescent waterborne amino-resin fire-retardant coating for wood (C) was synthesized and its fire-retardant and smoke-suppressant properties were investigated. The main film-builder of C was urea-formaldehyde resin blended with polyvinyl acetate resin. The intumescent fire-retardant system of C consisted of guanylurea phosphate (GUP), ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). Specimens of plywood painted, respectively, with a commercial intumescent fire-retardant coating (A), a synthesized coating (C), and the main film-builder of coating C (B), as well as an unpainted plywood (S-JHB), were analyzed by cone calorimetry (CONE). The results show a marked decrease in the heat release rate (HRR) and the total heat release (THR), an increased mass of residual char (Mass), a marked postponement in time to ignition (TTI) and a reduced carbon monoxide production rate (P CO). The smoke production rate (SPR) and total smoke production (TSP) of the plywood painted with coating C were observed with the CONE test. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than that of the commercial coating A. The thermo-gravimetric analysis (TGA) results of coating C and its film-builder B indicated that the thermal degradation process of B was slowed down by the addition of the intumescent fire-retardant system; the increase in the amount of charring of coating C was considerable.