The enhancement on thermal stability and charring–forming capability of nitration group

To obtain a novel charring agent, hexaphenoxy-cyclotriphosphazene (HCTP) was designed to be nitrified hexaphenoxy-cyclotriphosphazene (N-HCTP) by one step of nitration. Then the charring capability and thermal degradation behaviors of HCTP and N-HCTP were extensively investigated with the thermogravimetric analysis (TG) under pure nitrogen and air, respectively. TG results showed that nitration made the char residue yield of N-HCTP increase from 0 to 40% under nitrogen. And the effects of nitration made the char residue yield of N-HCTP increase from 0 to 2.3% under air. Meanwhile, TG was used to show the effect of nitration in inducing charring of acrylonitrile–butadiene–styrene under nitrogen. With 30% addition of N-HCTP, the char residual yield increased from 0.9 to 22%. Then TG/FTIR was used to research their gaseous products and their releasing intensity during decomposition. The TG/FTIR showed that the nitration made the decomposition of N-HCTP completely different from that of HCTP.