Flame retardancy and thermal degradation mechanism of epoxy resins composites based on a PEPA-substituted polyphosphoramide

摘要

A series of flame retardant epoxy resin composites with different content of PEPA-substituted polyphosphoramide (PSA) were prepared. The flame retardancy of EP/PSA composites was evaluated by UL-94 vertical burning test and the pyrolysis combustion flow calorimetry (PCFC). With the incorporation of 20 wt% PSA, the EP/PSA composites could reach the UL-94 V-0 rating and remarkable reduction of heat release rate could be observed. The thermal degradation mechanisms of the EP/PSA composites were investigated by Fourier transform infrared spectra (FTIR). FTIR analysis indicated that PSA could catalysis the decomposition of EP at lower temperature. The thermal degradation kinetics results of EP and EP/PSA composites by the Kissinger method showed that the apparent activation energy (E_a) reduced with incorporation of PSA, which indicated PSA could efficiently catalysis and promote the char forming process of EP.