Influence of chitosan-centered additives on flammable properties of vinyl ester matrix composites

This study focused on the effects of novel chitosan-ammonium polyphosphate, chitosan, and ammonium polyphosphate additives on the flammable properties of a vinyl ester matrix. A general mechanical process used for reinforcing additives within the matrix, and composites fabricated by the solution casting method through a general mechanical process. The influence of the additives on the resin observed through Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and pore size/surface area evaluation of the additives using  the Brunauer–Emmett–Teller analysis. The effect of the different amounts (1, 2, and 3 wt%) of additives on the flammability (horizontal and vertical burn test [UL94], LOI and microcalorimeter test), thermal, and mechanical (dynamic mechanical analysis and flexural test) properties of the vinyl ester composites were investigated. Reinforcement by 3 wt% NCSAPP resulted in an excellent fire extinguishing property (UL-94) with a low peak heat release rate (451 W/g) and appreciably improved mechanical properties. Hence, this study is suitable for the development of sub-structural materials.