ABSTRACT This study investigates the development of a biobased thermoplastic elastomeric biocomposite based on thermoplastic starch (TPS) dynamically vulcanized with natural rubber (NR), epoxidized natural rubber (ENR25 and ENR50), and reinforced with 20 phr rice husk ash (RHA). The effects of rubber polarity and filler incorporation on mechanical, thermal, and environmental performance were comprehensively examined. Among all formulations, ENR50/TPS/RHA20 exhibited the most balanced properties, achieving tensile strength of 5.3 MPa and elongation at break of 410%, compared to 1.0 MPa and 440% for NR/TPS. TSSR analysis revealed superior thermal elasticity with an initial stress of 0.18 MPa and high relaxation temperatures ( T 10 ≈ 80°C, T 50 ≈ 155°C, T 90 ≈ 190°C). Thermogravimetric results indicated a final degradation temperature of 421°C and 9.8% char residue, confirming improved thermal resistance. Additionally, ENR50/TPS/RHA20 showed reduced water absorption (∼22.5% at 72 h) and minimal weight loss (<25%) after 60 days of soil burial. These findings demonstrate that the combination of polar ENR and silica‐rich RHA significantly enhances interfacial adhesion, mechanical reinforcement, and environmental stability, making ENR50/TPS/RHA20 a promising candidate for sustainable elastomer applications. The novelty lies in the synergistic reinforcement strategy: using different ENR polarities (ENR25, ENR50) with biobased RHA to simultaneously improve mechanical, thermal, and environmental properties of TPS‐based biocomposites.
Pichaiyut et al. (Thu,) studied this question.