Improvement on flame retarding performance: preparation and characterization of water-based indoor paints with addition of boric acid

Abstract

The design of a fire-protection of the construction materials for buildings has become necessary to reduce the risk of a serious fire with the increasing population and increasing urbanization. During a fire, to extend the time of interfering with a building, water-based indoor paints have received attention; however, the performance and flame retardant property of these paints need to be improved. In this study, boric acid, which is the product of boron, was chosen as an additive for a flame retardant to develop this performance of the prepared paints due to its advantages such as a low toxicity, odorless, colorless, and corrosion resistance. In order to investigate the effect of different weight ratios of boric acid, water-based indoor paints have been prepared with the addition of 5%, 10%, and 20% (w/w) of boric acid. In addition, the synergistic effect of boric acid and melamine on the flame retarding performance of the prepared paints was also investigated. The physicochemical properties, flammability characteristics and thermal properties were analyzed by Fourier transform infrared spectroscopy (FTIR), limiting oxygen index (LOI), and thermogravimetric analysis (TGA), respectively. The results demonstrated that the characteristic peaks of boric acid were observed in the prepared paints. The prepared sample (P6) including 20% (w/w) of boric acid showed a more significant enhancement in flammability behavior from 24% to over 55% than that of containing melamine and boric acid. Moreover, the results of the thermogravimetric analysis demonstrated that increasing the amount of boric acid showed more effectiveness on the property of flame retardancy among the prepared paints due to the result of the mass-loss rate. In conclusion, the prepared indoor paint, P6, has served as a suitable option to halogen-based paints for the enhancement of the flame retardancy of the water-based indoor paints.