Fabrication of zinc oxide‐coated microcrystalline cellulose and its application in truck tire tread compounds

Abstract The severe threat to aquatic environment from zinc oxide (ZnO) in tread debris has become a serious issue for tire manufacturers. Various attempts including the utilization of composite ZnO have therefore been made to reduce ZnO content in tread compounds. In this study, a new composite ZnO was prepared by depositing ZnO nanoparticles on microcrystalline cellulose (MCC) through hydrothermal reactions, called M‐ZnO. After characterization by various techniques, cure activation efficiency of M‐ZnO in truck tire tread compound was investigated and compared with that of active ZnO (A‐ZnO). The results showed that M‐ZnO contained approximately 66.7% w/w of ZnO and had comparable specific surface area to A‐ZnO. Regardless of the ZnO type, crosslink density increased with increasing ZnO content up to 3 phr leading to the improved mechanical properties of the rubber vulcanizates, that is, hardness, modulus, and abrasion resistance. Tensile and tear strengths, however, were found maximum at 2 phr of both A‐ZnO and M‐ZnO. Although wet grip index was independent of ZnO content, rolling resistance tended to reduce with increasing ZnO content. The results clearly show the great potential of utilizing M‐ZnO to replace conventional A‐ZnO in tread compounds when more stringent environmental regulations are imposed.