Influence of Hevea brasiliensis Leaf Fillers and Clay Reinforcement on the Thermal Stability of Polymer Composites

Abstract

This study aimed to evaluate the thermal behaviour of Hevea brasiliensis leaf (HBL)–polyester composites enhanced with clay and to determine how different clay loadings affect composite weight loss under high-temperature conditions. Natural fibre composites were prepared with 1%, 3%, and 5% clay, and their thermal stability was measured using Thermogravimetric Analysis (TGA) under nitrogen flow to a maximum temperature of 600 °C. Results indicate that increasing the clay content led to higher residual mass after thermal degradation, demonstrating improved thermal stability, although the onset of degradation occurred at lower temperatures for composites with higher clay content. The study indicates that clay improves the structural integrity of the composite through intercalation and lamellar interactions with HBL, while untreated fibres and the polymer matrix affect the degradation process. For future work, alkaline treatment of both HBL and clay is recommended to achieve improved bonding and thermal properties.