Kinetics of thermal decomposition of PMMA at different heating rates and in a wide temperature range.

Highlights • PMMA pyrolysis kinetics was studied in the broad temperature range of 315÷500 °C. • The kinetic data were obtained using first order model and iso-conversion method. • The kinetic data validity was verified by modeling reaction rate versus temperature. • The kinetic parameters may be used in numerical simulation of PMMA combustion. Abstract Using the methods of differential mass-spectrometric thermal analysis (DMSTA), thermogravimetric analysis (TGA), microscale combustion calorimetry (MCC), and fast pyrolysis (FP), thermal decomposition of high-molecular-weight polymethylmetacrylate (PMMA) has been investigated in the temperature range of 315÷500 °C. Based on these data, the kinetic parameters (the activation energy, the pre-exponential factor) were obtained of a one-step pyrolysis reaction in supposition of a first-order reaction using simple mathematical fitting and an iso-conversion method. Validity of the obtained kinetic parameters was verified by comparing the experimental data on dependence of the decomposition rate on temperature in the broad range of the heating rates with the results of simulating the above dependence, using these kinetic parameters. These parameters, obtained in the broad temperature range, may be further used in numerical simulation of PMMA combustion under fire conditions and for assessing the polymer's flammability. [ABSTRACT FROM AUTHOR]