Biomaterial arginine encountering with UV grafting technology to prepare flame retardant coating for polyacrylonitrile fabric

Abstract In order to endow polyacrylonitrile (PAN) fabric with excellent thermal and flame retardant properties, glycidyl methacrylate (GMA) was grafted on the surface of PAN fabric by UV-induced grafting technology to obtain GMA grafted PAN fabric (PAN-g-GMA). Next, L-Arginine was introduced to PAN-g-GMA (PAN-g-GMA/Arg) through the reaction of the amino groups in L-Arginine and the epoxy groups in GMA units. Then the flame retardant PAN fabric (FR-PAN) was prepared via the phosphorylation of PAN-g-GMA/Arg. When the grafting percentage was up to 13.5 wt%, the residual char of FR-PAN at 800 °C reached 51.6 wt%, indicating improved thermal stability. In addition, compared to PAN sample, the peak of heat release rate (PHHR) and total heat release (THR) of FR-PAN were remarkably decreased by 36.3% and 8.1% respectively, demonstrating excellent flame retardancy. Moreover, the elongation at break of FR-PAN fabric was increased by 53.6%. The cyclization of PAN induced by phosphoric acid reduced the chain breakage and inhibited the degradation of PAN. Moreover, the introduced amino acids delayed the release of HCN and other pyrolysis volatiles, meanwhile, the released NO and other non-combustible gases prevented oxygen from entering the combustion zone. This work presents a facile strategy for the application of amino acid materials in flame retardant PAN materials.