Improved fatigue resistance of thermoplastic elastomer-filled natural rubber composites

Improving fatigue life and crack growth resistance is a sustainable approach to resolving end-of-life recycling challenges associated with cross-linked rubbers. This research paper aims to explore the influence of SIS (styrene-isoprene-styrene triblock copolymer) as a thermoplastic elastomer on the crack initiation and propagation resistance of NR rubber compound reinforced by dual carbon black-silica hybrid fillers. A comprehensive array of crack growth analyses including Die-C and Trousers tearing, tearing pattern assessments, fatigue flex cracking, and wear resistance tests were carried out, and the findings were elucidated by analyzing the composite morphology, and the viscoelastic loss behavior. SIS-containing samples exhibited outstanding fatigue cracking resistance, successfully enduring over 100,000 loading cycles without showing any signs of damage. Also, an improvement of 64 % in the Die-C tearing resistance, and 15 % in wear resistance were only part of the positive aspects of SIS presence in the NR composites. Having analyzed the Payne effect, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) test, it is illustrated that the enhancement in durability primarily stems from new sources of viscoelastic dissipation and a better state of filler dispersion within the material.