Thermal stability evaluation of sweet sorghum fiber and degradation simulation during hot pressing of sweet sorghum–thermoplastic composite panels

• Thermal degradation kinetic parameters of sweet sorghum were calculated.
• Thermal degradation of sweet sorghum chemical components was simulated.
• Thermal degradation of sweet sorghum during hot pressing process was simulated.
• Independent parallel reaction model accurately predicted the thermal degradation of sorghum.

An understanding of the thermal behavior of natural fibers is critical in efficiently converting them into composites under heat and pressure. The objectives of this study were to evaluate the thermal stability of sweet sorghum fiber and simulate its thermal degradation during hot pressing into composite panels. Thermal stability of sweet sorghum was analyzed using thermogravimetric analysis, and its thermal degradation during the hot pressing process was simulated based on kinetic parameters calculated using the ASTM E1641 method, Friedman method, and independent parallel reaction model (IPRM). The results demonstrate that experimental testing data and IPRM prediction results are in accordance. Sorghum degradation ranged from 5.4% at the surface to 2.0% at the core of the panel after 10 min of hot pressing at a platen temperature of 160 °C. The results of this study will assist with consolidation of sorghum fibers into products under heat.