CHARACTERIZATION AND PROPERTIES OF VERMICULITE ON WATER-BASED ACRYLIC FIRE RETARDANT COATING

Fire retardant coating (FRC) is a vital element in the structural industry since there is an increase of the fire hazards especially in housing area. The importance of FRC is not only to provide a heat barrier to insulate the fire, but also does not generate smoke that toxic to the occupants during fire hazards. Therefore, in this research, the new formulation of water-based FRC which include a water-based acrylic resin and vermiculite as an additive was developed. The aims of this research study are to investigate the significant effect of vermiculite in enhancing the FRC and the role that acrylic resin can play. There were four formulations of coating (F1 until F4) with two different acrylic media (matt and gloss acrylic) and with and without vermiculite were applied to galvanized steel plate with thickness of 1 mm. The four formulations had been analyzed to identify the peaks. The elements of two acrylic media and vermiculite, the thermal degradation and surface morphology were investigated by using Fourier transformed infrared (FTIR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, thermogravimetric analyses (TGA), and scanning electron microscopy (SEM). The heat resistance of coating was investigated by performing fire protection test for 100 minutes. For mechanical property, the shear test was conducted to measure the adhesion strength by applying the shear forces by following the ASTM 3163. TGA results for formulation F3 and F4 with presence of vermiculite showed the increase of thermally stable residue and the temperature reading from fire protection test was reduced about 150oC. F3 was found giving the lowest temperature of 200oC at 100 minutes compared to the other formulations. The microstructure of F3 had small porosity which is around 5 – 20 μm was observed and the shear strength of F3 was the highest compared to others, which improved about 2 times. A significant increase of shear strength, the insulation of heat and good char structure of F3 were related to the composition of the vermiculite which are aluminosilicate and enhanced with the elements in the matt acrylic i.e. SiO2 and Al2O3 that were not presence in the gloss acrylic.