A detailed bond stretch model of thermal decomposition

Abstract

Thermal decomposition is caused by the breaking of the bonds of polymer chains after they are stretched to a length threshold. Any factors that affect the bond stretch can affect the thermal decomposition process. The physical processes like glass-transition changes and the physical configuration of the polymer chains affect the stretch mechanism apparently. Thus, glass-transition and molecular weight may be reflected in the thermal decomposition process characterized by the thermogravimetric (TG) or differential thermogravimetric (DTG) curves. This idea was confirmed by the thermal decomposition of solid poly-α-methyl styrene (PαMS). The experiment results showed that the DTG curves change suddenly near the glass-transition temperature, and the activation energy goes up with an increase of molecular weight, which indicates that the physical process is vital in the thermal decomposition process.