Intumescent Waterborne Modified-amino-resin Fire-retardant Coating For Wood

Wood material gets more of people's favor for its particular physical mechanical characteristics and excellent environmental property using at home and public;however,there are also the fire disasters to our life and property because of the wood material's flammability. The intumescent coatings which is simple construction and low cost emerges as the times require.It can protect the substrate and decrease the fire hazard by the foamed char.In this paper,an intumescent waterborne modified-amino-resin fire-retardant coating for wood was synthesized by orthogonal experiments.The main film-builder was urea-formaldehyde resin blended with polyvinyl acetate resin,and the intumescent fire-retardant system was guanyl-urea phosphate(GUP)-ammonium polyphosphate(APP)-pentaerythritol (PER)-melamine(MEL).GUP as the low temperature dehydration catalyst was brought in the system and formed the composite catalyst with APR In the intumescent system,PER was the charring agent and MEL was the blowing agent.The fire-retardant time was about 1418s and the expansion multiple of synthesized coating was more than 70 times.The rheological characteristic of the intumescent waterborne modified-amino-resin fire-retardant coating was tested with a rotary rheometer.This coating was easy to spraying and brushing,and difficult to sedimentation and coacervation under the environment of low shearing rate such as long-term storage or transportation.The specimens of plywood painted respectively with a commercial intumescent waterborne fire-retardant coating(A),synthesized coating(C),the main film-builder of synthesized coating(B) and the unpainted plywood(S-JHB ),were comparatively studied by cone calorimeter(CONE) at a heat flux of 50kW·m^-2 and a gas flow rate of 24L·S^-1.The heat release and smoke release of the synthesized coating painted plywood(C) were decreased observably,and the time of ablative-resistant greatly prolonged.The structure and properties of intumescent waterborne modified-amino-resin fire-retardant coating and its foamed char were investigated by TG,DSC,FTIR,SEM-EDAX and XPS.The weightlessness rate of the synthesized coating was reduced obviously,and the carbon residue ratio was 1.6 times higher than film-builder's.The composite dehydration catalysts interacted brightly at the different range of temperature,and intumescent fire-retardant system had approved synergistic reaction with the film-builder.The majority of organic obviously reduced,or even disappeared in the foamed char.There was much more N element in the sealing foamed-char surface than in depth,though the compact foamed-char was composed by C,O,P and N elements.The overall fire-retardant and smoke suppressant performance of the intumescent waterborne modified-amino-resin fire-retardant coating were much better than the commercial intumescent waterbome fire-retardant coating.