Flame retardance enhancement of polyacrylonitrile with dimethyl vinylphosphonate

To obtain a polyacrylonitrile (PAN) material with highly thermal stability and flame retardance properties, a novel P(AN-co-DMVP) copolymers were successfully synthesized by randomly copolymerization. According to thermogravimetry analysis, it revealed that incorporating dimethyl vinylphosphonate (DMVP) into the PAN chains can perform outstanding thermal stability. Furthermore, the limiting oxygen index increased from 18.6% to 30.0% with addition of 22.6 wt% DMVP. The results of cone calorimetry tests certified that the peak-heat release peak and total heat release of P(AN-co-DMVP22.6) were remarkably dropped by 70% and 33%, respectively, suggesting excellent flame retardance. The relationship between copolymer structures and flame-retardant performance was systematically investigated by X-ray photoelectron spectroscopy, Raman spectroscopy, thermogravimetric analysis-Fourier transform infrared and Pyrolysis gas chromatography/mass spectrometry. A comprehensive flame-retardant mechanism has been proposed that DMVP plays a role in both the gaseous phase and the condensed phase.

Automated summary

A novel P(AN-co-DMVP) copolymer with excellent thermal stability and flame retardance properties was successfully synthesized, showing a significant increase in oxygen index and a decrease in heat release with the addition of DMVP. The relationship between copolymer structures and flame-retardant performance was systematically investigated using various analytical methods, proposing a comprehensive flame-retardant mechanism involving DMVP in both the gaseous and condensed phases.