The mechanical and thermal properties of natural rubber/zinc methacrylate composites by latex compounding techniques

Abstract Zinc methacrylate (ZDMA) is a typical ionic compound that readily reacts with rubber molecules. In this work, a new approach was developed to prepare natural rubber (NR)/ZDMA composites with a lower loading of ZDMA. ZDMA was prepared by the reaction of methacrylic acid (MAA) and ZnO in an aqueous solution. Then the NR/ZDMA masterbatches were obtained by latex compounding techniques; followed by vulcanization either with dicumyl peroxide (DCP) or together with a sulfur‐based vulcanization system (SVS). The results of mechanical property tests showed that the increment of ZDMA will decrease the cure rate index and increase crosslink density. When the content of ZDMA was more than 8.7 phr, not only the 300% and 500% modulus, tensile, and tear strength of NR/ZDMA composites were improved remarkably, but also the aging resistance and thermal stability were improved. When the amount of ZDMA is less than 8.7 phr, SVS shows a certain synergistic vulcanization effect with DCP. When 20 phr ZDMA was added, the tensile and tear strength increased by 86.5% and 60.1%, respectively, when contrasted to NR cured with traditional SVS. The structural characterization results revealed that ZDMA and Poly‐ZDMA have been formed and act as a reactive filler in the NR matrix.