A novel zinc complex for rubber vulcanization: Enhanced mechanical properties and reduced environmental impact through <scp>ZnO</scp> substitution

Abstract Decreasing zinc consumption in vulcanization processes of rubber represents a major environmental issue for the rubber industry. To overcome this problem, a novel method has been developed based on replacing conventional zinc oxide (ZnO) with zinc dodecyl sulfate (Zn(DS) 2 ) in the vulcanization of styrene‐butadiene rubber (SBR). The amount of free zinc incorporated in the rubber composites has been quantified by flame atomic absorption spectroscopy (FAAS). Results indicated a reduction in zinc content in samples containing Zn(DS) 2 by 34%–77% as compared with the control sample containing 3 phr ZnO. Further investigations have also been performed to find out the effect of Zn(DS) 2 on crosslink density, thermal and mechanical properties, curing characteristics, and dynamic mechanical behavior by swelling tests, rheometric measurements, tensile tests, thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). Replacement of ZnO with Zn(DS) 2 has increased the crosslink density significantly, by as much as 105%, thus providing evidence for enhanced availability of the Zn cations to the accelerator. Also, increases in tensile strength and ice grip and reduction in rolling resistance by 30%, 101%, and 13%, respectively were observed. Overall, Zn(DS) 2 shows promise as a viable alternative to traditional ZnO‐based activators in the tire industry by increasing performance and decreasing zinc levels. Highlights Zinc dodecyl sulfate (Zn(DS) 2 ) replaces zinc oxide in rubber vulcanizate. Unreacted zinc content decreases by 77% with Zn(DS) 2 incorporation. Zn(DS) 2 increases crosslink density in the rubber matrix. Zn(DS) 2 enhances tensile strength, ice grip, and rolling resistance.