Performance Enhancement of Dynamically Cured ENR / EVA / PP Thermoplastic Vulcanizates via Compatibilization and Rubber‐to‐Plastic Ratio Optimization

ABSTRACT This study investigates the influence of compatibilizer type and rubber‐to‐plastic ratio on the performance of dynamically cured epoxidized natural rubber (ENR‐25)/ethylene–vinyl acetate (EVA)/polypropylene (PP) thermoplastic vulcanizates (TPVs). Three in‐house synthesized reactive compatibilizers, phenolic resin‐modified polypropylene (PhHRJ‐PP, PhSP‐PP), and maleic anhydride‐grafted PP (PP‐g‐MA), were evaluated. Among them, PhHRJ‐PP yielded the best performance, achieving a tensile strength of 11.44 MPa, an elongation at break of 295%, and high toughness at the optimal ENR/EVA/PP composition of 30/30/40 (corresponding to a rubber‐to‐plastic ratio of 60/40, wt%). This composition also demonstrated a refined phase morphology, with rubber domains averaging 1.77 ± 0.27 μm, elevated storage modulus, low tan δ , and enhanced complex viscosity. Additionally, it showed the highest aging resistance, retaining 85.49% of tensile strength after thermal exposure. Solvent resistance and thermal degradation behavior were found to depend on both blend composition and PP crystallinity. These results underscore the critical role of interfacial adhesion, dynamic vulcanization, and morphological control in optimizing TPV performance. The findings provide a valuable framework for designing bio‐based, recyclable elastomeric materials suitable for high‐performance, mechanically demanding applications.