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.

A feasible way to modify microcrystalline cellulose powder and its reinforcing effect for NBR composites

“…Therefore, some researchers have made a great attempt to blend microcrystalline cellulose powder (MCC, on the microscale) with rubber matrix on an industrial open two-roll mill. 4,39,40 Before masticating, MCC was modified by silane coupling agents 4,39 or zinc oxide 40 to get better dispersion and interfacial adhesion with the rubber matrix. However, these interfacial interactions were only molecular chain entanglements, resulting in a weak surface interaction and a moderate improvement in the properties of the rubber/MCC composites.…”

“…As we can see, these three processes are very complicated and not easy to carry out in the rubber industry due to the high investment required. Therefore, some researchers have made a great attempt to blend microcrystalline cellulose powder (MCC, on the microscale) with rubber matrix on an industrial open two‐roll mill 4,39,40 . Before masticating, MCC was modified by silane coupling agents 4,39 or zinc oxide 40 to get better dispersion and interfacial adhesion with the rubber matrix.…”

Preparation of Zinc Oxide with Core–Shell Structure and Its Application in Rubber Products

“…The rubber tire industry represents the largest consumer of zinc oxide, with approximately 50% of total zinc oxide usage being attributed to this industry [ 7 ]. Currently, micron-sized ZnO is used primarily as the curing active agent in the tire industry, and only a portion of the ZnO is involved in the activation of the curing reaction.…”

On the In Vitro and In Vivo Hazard Assessment of a Novel Nanomaterial to Reduce the Use of Zinc Oxide in the Rubber Vulcanization Process

“…Accordingly, the Environmental Protection Agency (EPA) defined the reduction of ZnO level, a compelling matter in rubber and tire production in addition to in the end-oflife tire recycling treatments [17]. In this context, several candidate materials have been proposed to reduce the amount of the traditional microcrystalline ZnO activator and to improve the efficiency of the curing process at the same time [18][19][20][21]. Recently, a novel activator composed of ZnO nanoparticles (NPs, here after ZnO-NP@SiO 2 -NP) anchored to silica filler NPs was recently proposed, which behave simultaneously as curing activator and filler (i.e., double function filler), allowing a 50% reduction of the ZnO amount currently used in the production of rubber composites for tires [22,23].…”