Effect of Pineapple Leaf and Carboxymethyl Cellulose Hybrid Fibers on Properties of ENR / EPDM Blends: Dynamic Mechanical, Weathering and Thermo‐Mechanical Properties

ABSTRACT Epoxidized natural rubber (ENR) and ethylene propylene diene monomer (EPDM) composites filled with pineapple leaf fiber (PALF) and carboxymethyl cellulose (CMC) hybrid fillers were prepared using the melt mixing process. EPDM, known for its excellent thermal stability, weathering resistance, and flexibility, complements the properties of ENR, making the blend suitable for high‐performance applications. The crosslink propagation of rubber molecules, along with their physical properties and resistance to aging and weathering, was investigated. Additionally, the relaxation behavior was analyzed using the temperature scanning stress relaxation (TSSR) method, and the thermal stability of ENR/EPDM composites was also examined using the TSSR method. The degree of filler dispersion was correlated with the observed morphologies. It was found that the incorporation of CMC decreased scorch and cure times, as CMC contains polar groups that can interact with the ENR molecules. Furthermore, torque difference, modulus, and aging properties increased with higher PALF/CMC loadings. This effect is due to the reinforcement of the fillers, which enables strong interactions with the polar epoxide groups, forming a stronger interface between the fiber and the ENR/EPDM matrix. CMC also enhanced PALF dispersion, reducing aggregation and forming a strong interfacial network within the ENR/EPDM matrix. Increasing CMC content further improved the relaxation modulus owing to the enhanced dispersion of PALF and CMC within the ENR/EPDM matrix.