A novel fire retarded polyacrylonitrile copolymer (FR-PAN) was obtained via copolymerization of acrylonitrile with O,O-diethyl-O-allyl thiophosphate (DATP). The non-isothermal decomposition kinetics of the FR-PAN in O2 were studied by TG-DTG techniques, and the fire retardance of the FR-PAN was investigated by the limiting oxygen index (LOI) method. The activation energies of the major thermal decomposition of the FR-PAN were determined by using the Kissinger method and Flynn-Wall-Ozawa (FWO) method, respectively. With the selection of different mechanism models, the decomposition mechanism of the FR-PAN was obtained by using the Satava-Sestak method. The results show that the activation energies for the major thermal decomposition step of the FR-PAN are 119.62 kJ•mol－1 with the Kissinger method and 123.99 kJ•mol－1 with the FWO method, respectively. And the thermal decomposition mechanism of the major decomposition step of the FR-PAN is random nucleation and growth, with the mechanism function being G(α)＝－ln(1－α), and the reaction order being 1.

Key words: O,O-diethyl-O-allyl thiophosphate, fire retarded polyacrylonitrile, thermal decomposition, kinetics