Reverse Vulcanization of Monomers with Conjugated Bonds Double and Elemental Sulfur for S–S Bond Self-Healing Properties

In this paper, tung oil-linseed oil (TO-LSO) and styrene-linseed oil (STY-LSO) were used as raw materials of sulfur-rich copolymers, which were then reversed vulcanized with S₈ at 130°C, and the gel time of the reaction was recorded. At the same time, ¹H NMR, DSC, XRD, sodium sulfite titration and other characterization methods were used to measure the reaction degree, verify the conjugated structure to improve the reaction degree, and study the synthesis mechanism of sulfur-rich copolymer. The results show that the conjugated structure can improve the reaction degree. And when the proportion of TO and STY is 20 and 10% respectively, the reaction gel time is shortened, the reaction degree is greatly deepened, and the effect of promoting polymerization can be significantly obtained. The synthesis mechanism of copolymer is the result of conjugated structure and diallyl group. The self-repair of sulfur-rich copolymers at different temperature and holding time by hot press shows that poly(20-TO-LSO-50S) can realize the S‒S bond self-repair after being compressed at 120°C for 4 h, and the surface of polymer disc was smoother and more uniform. However, poly(10STY-LSO-50S) can be repaired only after being compressed for 8 h. TO can not only enhance the synthesis process, but also enhance the performance of sulfur-rich materials and broaden the application field.