DOI: https://doi.org/10.55373/mjchem.v28i2.329

Keywords: Natural rubber latex, organic peroxides, accelerator-free, vulcanization, sustainability

Abstract

This study presents a sustainable approach to the vulcanization of natural rubber latex (NRL) films by eliminating conventional accelerators, which are known to produce nitrosamine by-products associated with health and environmental hazards. Instead, long-chain organic peroxides—dicumyl peroxide (DCP) and 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane (DHBP)—were utilized as accelerator-free curing agents. Latex compounds were prepared and subjected to detailed physicochemical and mechanical characterization, including swelling index, total solid content, pH, specific gravity, tensile strength, elongation at break, and modulus, along with FTIR analysis to assess the crosslinking behavior. The results indicate that DHBP outperformed DCP in promoting crosslink density and mechanical performance. At a concentration of 2 phr, DHBP showed a swelling index of 80%, total solid content of 29.03%, pH of 9.15, and specific gravity of 0.98. It also achieved superior mechanical performance, with a tensile strength of 14.26 MPa, elongation at break of 863.81%, and a modulus of 0.74 MPa. In comparison, DCP at the same concentration resulted in a swelling index of 82%, total solid content of 31.35%, pH of 8.95, specific gravity of 0.97, tensile strength of 12.37 MPa, elongation of 873.98%, and modulus of 0.86 MPa. These findings support the viability of organic peroxide-based vulcanization systems as environmentally friendly alternatives to traditional accelerators. By eliminating accelerator-derived nitrosamines, this approach contributes to safer industrial processing and aligns with the global shift toward green and sustainable rubber manufacturing. The study provides valuable insights for the development of next-generation NRL films tailored for applications requiring reduced toxicological impact without compromising material performance.