Abstract:

An intumescent waterborne amino-resin fire-retardant coating for wood?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,and the intumescent fire-retardant system of C was guanylurea phosphate(GUP)-ammonium polyphosphate(APP)-pentaerythritol(PER)-melamine(MEL). The specimens of plywood painted respectively with a commercial intumescent fire-retardant coating(A), synthesized coating?,the main film-builder of coating C(B)and the unpainted plywood(S-JHB),were analyzed by cone calorimetry(CONE). The results showed that remarkably decreased heat release rate(HRR) and total heat release(THR),increased mass of residual char(Mass),markedly postponed time to ignition(TTI),reduced carbon monoxide production rate(P_CO)and smoke production rate(SPR)and total smoke production(TSP)were observed in the CONE test of plywood painted with coating C. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than that of the commercial coating A. The thermogravimetric 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 and the charring of coating C was remarkable.

Key words: waterborne wood coatings, intumescent fire-retardant coatings, amino-resin, cone calorimeter, thermogravimetric analysis, smoke suppression