Thermal degradation behavior of optically active N-phenyl, N-benzyl, N-diphenylmethyl and N-triphenylmethyl maleimide polymers

Abstract Optically active poly(N-phenyl maleimide) (PPhMI), poly(N-benzyl maleimide) (PBzMI), poly(N-diphenylmethyl maleimide) (PDPMMI) and poly(N-triphenylmethyl maleimide) (PTrMI) obtained by a chiral anionic initiator have been studied by thermogravimetry from room temperature to 800 °C. The effect of the surrounding atmosphere on the thermal behavior of polymers is discussed. The activation energy of thermal degradation of the polymers in nitrogen and air was calculated by the Ozawa and Kissinger methods. It is found that the thermal degradations of PPhMI, PBzMI and PDPMMI are divided into two steps, the first step is slightly affected by oxygen; the second step is accelerated by oxygen. The thermal degradation of PTrMI is divided into multi-steps in which the initial steps are ascribed to the shedding of the side group and the last step is ascribed to the thermal degradation of poly(maleimide) backbone.