Preparation and properties of dynamic crosslinked styrene butadiene rubber

Abstract

As the second largest synthetic rubber after styrene butadiene rubber, cis-butadiene rubber (BR) is one of the important raw materials for automobile tires and cold-resistant products. Herein, a traditional rubber preparation process was used to introduce dynamic reversible bonds into BR based on an “imitative” click reaction. Compared with traditional complex self-healing techniques, this method is undoubtedly simpler and more efficient. Dynamic reversible bonds are able to break and recombine under the stimulation of external conditions, which endow rubber with self-healing properties. We use the small biological molecule lipoic acid (LA) as a cross-linking agent and cross-link LA and BR through mechanical compounding and hot press vulcanization to obtain self-healing butadiene rubber (BLA). In addition, BLA-(Zn²⁺) was further prepared by introducing Zn²⁺ to form metal-oxygen coordination bonds with carboxyl groups. And systematically studied the effect of Zn²⁺ on the mechanical properties and self-healing properties of cross-linked BR. Through the combined action of disulfide bonds, hydrogen bonds and Zn²⁺-O coordination bonds, BLA-(Zn²⁺) has better properties than BLA, the tensile strength can reach 3.76 MPa, and the repair efficiency is about 82 %. This simple preparation process is certainly more cost effective.