Interfacial Optimization and Thermomechanical Enhancement in NR/EVA TPVs via NR‐ <i>g</i> ‐IA Compatibilization

ABSTRACT This study introduces natural‐rubber‐grafted itaconic anhydride (NR‐g‐IA) as a renewable compatibilizer for dynamically cured natural rubber/ethylene–vinyl acetate (NR/EVA) thermoplastic vulcanizates (TPVs). NR‐g‐IA was synthesized via free‐radical grafting and incorporated at 1–15 wt% to evaluate its influence on interfacial adhesion, morphology, and thermomechanical performance. An optimal loading of ~7 wt% yielded a TPV with superior tensile strength and elongation (≈728%), the smallest rubber‐domain size (~1.3 μm), and the maximum TSSR index (0.61), indicating strong elastic energy storage. Dynamic and rheological analyses revealed a marked increase in storage modulus ( G′ ), reduced damping (tan δ), and enhanced complex viscosity ( η* ), confirming improved interphase coupling. Thermal analysis further confirmed improved stability, with degradation temperatures ( T d 1 / T d 2 ) shifting to 403°C and 497°C, respectively. Excess compatibilizer (&gt; 7 wt%) led to over‐coverage of the domain surface and subsequent domain coarsening, which reduced the overall performance. The combined morphological, rheological, and TSSR evidence demonstrates that NR‐g‐IA effectively bridges polar EVA and nonpolar NR phases through anhydride–ester interactions, yielding a finely dispersed, thermally stable, and elastically resilient TPVs. This study establishes NR‐g‐IA as a renewable and reactive compatibilizer for advancing sustainable, high‐performance rubber‐plastic blends.