Kinetic equations for thermal degradation of polymers

TL;DR

This paper develops kinetic equations based on fragmentation-annihilation concepts to model the thermal degradation of polymers, providing explicit solutions and numerical analysis that align well with experimental data.

Contribution

It introduces a new kinetic model for polymer degradation with explicit solutions and validates it against experimental results.

Findings

Model accurately predicts molecular weight decrease during thermal degradation.

Explicit solutions facilitate understanding of polymer breakdown processes.

Numerical simulations match experimental thermo-gravimetric data.

Abstract

Kinetic equations are analyzed for thermal degradation of polymers. The governing relations are based on the fragmentation-annihilation concept. Explicit solutions to these equations are derived in two particular cases of interest. For arbitrary values of adjustable parameters, the evolution of the number-average and mass-average molecular weights of polymers is analyzed numerically. Good agreement is demonstrated between the results of numerical simulation and experimental data. It is revealed that the model can correctly predict observations in thermo-gravimetric tests when its parameters are determined by matching experimental data for the decrease in molecular weight with exposure time.