Thermal Degradation Kinetics of Natural Fibers: Determination of the Kinetic Triplet and Lifetime Prediction

Natural fibers have been widely employed in different fields as composite materials. However, the thermal behavior of natural materials is not fully understood since the chemical components chemically interact with each other. Put simply, the thermal degradation kinetics of natural fibers are of crucial importance in the academic and industrial fields. This study objectively fully investigated the thermal behavior of different natural fibers using the thermal kinetic method criteria, as described by the ICTAC (International Committee of Thermal Analysis and Calorimetry). The kinetic triplet (activation energy, pre-exponential factor, and reaction mechanism) was determined as a function of the conversion degree. For all plant fibers, the results indicated an autocatalytic process with an average activation energy and pre-exponential factor of 200 kJ·mol−1 and 40 s−1, respectively. The activation energy can be mainly attributed to the cellulose component, while the pre-exponential factor is due to the possible compensation effect as a mathematical artifact of the Arrhenius-based equation. Finally, the lifetime prediction of the plant fibers was estimated using the pre-determined kinetic triplet parameters to estimate the plant fiber stability under isothermal conditions.