Improved adhesion properties of natural rubber to polyamide cord through mussel-inspired adhesive

A facile and efficient mussel-inspired bonding method is developed to improve the interfacial adhesion of polyamide cord/rubber composites by introducing silica coated with polydopamine (PDA). PDA layer is deposited on the silica surface by simply dipping the silica particles into an alkaline dopamine solution. The core–shell structure can endow polyamide cord/rubber high adhesion strength through the strengthening effect of silica on the adhesive transition layer. This new dipping system displays low toxicity, high efficiency and simplicity, which is crucial to rubber industry and human health. Compared with the original cord, the pulled-out force of our developed dipped cord is increased by 63%. In addition, the adhesive property of our developed dipped cord/rubber is characterized, and the adhesive mechanism is also studied in detail. Bionic design of mussels has provided a new way to enhance the adhesion between polyamide cord and rubber in rubber industry.