Thermal Stability of Bio-Based Materials under Variable Processing Conditions

Abstract

Bio-based materials such as polylactic acid, starch, cellulose, polyhydroxyalkanoates, lignin and chitosan are increasingly used to replace petroleum-derived plastics, but their limited thermal stability narrows the window in which they can be processed. This article examines how thermal stability changes under variable processing conditions, including heating rate, temperature profile, atmosphere, moisture content, shear, residence time and the presence of additives. Thermogravimetric and calorimetric techniques are reviewed together with isoconversional kinetic methods that convert experimental curves into activation energies and lifetime predictions. The discussion shows that degradation is not a fixed property of a material but a response to its processing history: moisture promotes hydrolysis, oxygen accelerates oxidative chain scission, and high shear and long residence times add mechanical and thermal damage. Stabilisation strategies, including drying, chain extenders, antioxidants and nanofillers, are assessed for their ability to widen the safe processing window. The numerical values quoted are representative of typical literature trends and serve to illustrate the analysis. The article concludes with practical guidance for manufacturers who wish to process bio-based materials without sacrificing mechanical performance or product consistency.