Abstract: Thermal decomposition of aluminum methyl cyclohexyl hypophosphite（Al（MHP））filled epoxy（EP） composite were investigated with thermogravimetric analyses（TG） and fourier transform infrared spectroscopy（FTIR）. The interaction between component during thermal decomposition process was explored with theoretical arithmetic，adopted FTIR to analyse the product of decomposition. Results show that adding Al（MHP）into EP causes the initial decomposition temperature of composite shifting to the lower temperature，but results in a decrease of degradation rate and an increase of carbon forming. FTIR results show the residues are rich in C and P element，The compound with C and P are beneficial for the thermal stability of the composite.

Key words: dialkylhypophosphite, flame retardant, epoxy, thermal decomposition