Integration of Peroxide-Cured Rubber/Rubber Through Covalent Grafting of a Thiol-Linked Molecular Layer

A simple, nonfluid, and direct adhesion method was developed to adhere cured rubber/rubber via grafting of a molecular layer of a triazine-based silane coupling agent without any pretreatment. During peroxide curing, oxide functional groups that can react with silanol groups were automatically fabricated on the surface of acrylonitrile–butadiene rubber (NBR) during primary processing at different curing temperatures. After the molecular layer was grafted onto the cured rubber surface, nonfluid adhesion between the cured NBR surfaces was induced. An NBR/NBR joined body was obtained and exhibited high adhesion strength with cohesive failure. The presented method is rapid, inexpensive, and environmentally friendly and can resolve the persistent problems of spew, extra adhesive, and rugose interface in the “fluid adhesion” of adhesive adhesion and vulcanization bonding processes. In addition, this method does not require secondary processing for inducing the formation of functional groups and should, therefore, be particularly valuable in industrial adhesion applications.