Nucleophiles realizing the reduction of ZnO content for vulcanization accompanied by the improvement in thermo‐oxidative resistance for vulcanized isoprene rubbers

Abstract

At present, vulcanization is an indispensable process in rubber industries and ZnO is an important ingredient in vulcanization reactions. However, ZnO is toxic to aquatic organisms and the use of ZnO is unfavorable to the sustainable development of rubber industry. The decrease of ZnO content without the reduction in properties of rubbers has been an open question in rubber industries. In this work, our group designs nucleophiles with an ability to open the ring of sulfur. With the decrease of ZnO content, the addition of nucleophiles maintains the ring‐opening capacity of sulfur. As a result, changes in several properties of rubbers such as tensile strength, tear strength, and crosslinking density are negligible with the reduction of ZnO content. Also, the thermo‐oxidative resistance of rubbers improves dramatically with the decrease of ZnO content and addition of nucleophiles. Through designing nucleophiles to reduce the content of ZnO, this work provides a strategy to develop sustainable rubber industries.