THERMAL-DEGRADATION BEHAVIOR OF OPTICALLY-ACTIVE N-PHENYL, N-BENZYL, N-DIPHENYLMETHYL AND N-TRIPHENYLMETHYL MALEIMIDE POLYMERS

Optically active poly(N-phenyl maleimide) (PPhMI), poly(N-benzyl malei mide) (PBzMI), poly(N-diphenylmethyl maleimide) (PDPMMI) and poly(N-tr iphenylmethyl maleimide) (PTrMI) obtained by a chiral anionic initiato r have been studied by thermogravimetry from room temperature to 800 d egrees C. The effect of the surrounding atmosphere on the thermal beha vior of polymers is discussed. The activation energy of thermal degrad ation of the polymers in nitrogen and air was calculated by the Ozawa and Kissinger methods. It is found that the thermal degradations of PP hMI, PBzMI and PDPMMI are divided into two steps, the first step is sl ightly affected by oxygen; the second step is accelerated by oxygen. T he thermal degradation of PTrMI is divided into multi-steps in which t he initial steps are ascribed to the shedding of the side group and th e last step is ascribed to the thermal degradation of poly(maleimide) backbone. (C) 1998 Elsevier Science Limited. All rights reserved.