Detailed kinetic analysis of slow and fast pyrolysis of poly(methyl methacrylate)-Flame retardant mixtures

Abstract

In this study, thermal decomposition kinetics of poly(methylmethacrylate) (PMMA) is investigated in the presence of a phosphorus-based flame retardant (Exolit®) under slow and fast pyrolysis conditions. Multi-Gaussian distributed activation energy model (DAEM) is employed to determine the kinetic parameters at slow heating rates. The multi-Gaussian DAEM with five parallel independent reactions predicts well the experimental mass loss and differential mass loss profiles. The incorporation of 3 and 5 wt.% Exolit® in PMMA delays the decomposition temperature and slows down the rate of PMMA pyrolysis. Isothermal fast pyrolysis is carried out in the temperature range of 400−700 °C at short time intervals of 2−150 s. The rate constant of decomposition of PMMA + 5 wt.% Exolit® mixture was lower than that for pure PMMA. Through analytical pyrolysis coupled with Fourier transform infrared spectroscopy it is shown that the addition of Exolit® to PMMA significantly delays the evolution of methylmethacrylate, which is the major pyrolysate.