Olefins, sulfur halides
Synthesizing vulcanizing agents with olefins and halogenated sulfur as raw materials is a relatively common method in my country's industry. Halogenated sulfur and olefins generate halogen-containing organic vulcanizing agent in the presence of a catalyst, and then undergo a dehalogenation process to obtain the organic vulcanizing agent. At the beginning of the century, Chinese scholar Huang Jinxia proposed to use sulfur chloride and isobutylene as raw materials to synthesize organic vulcanizing agents. The organic vulcanizing agent synthesized by this method has high sulfur content, high stability and low corrosivity, but this method is used in the synthesis of organic vulcanizing agents. During the production process, a large amount of waste gas, waste water and liquid waste will pollute the environment.
In recent years, many documents have successively reported the improved method of the synthesis route. For example, Yang Jingpei proposed to synthesize the organic vulcanizing agent containing impurities in two steps under a closed pipeline, and then obtain the pure organic vulcanizing agent through the steps of separation, dehydration, and purification. The process is carried out in a closed pipeline, which avoids environmental pollution by waste gas and waste liquid. However, this method has a complicated synthesis process and high equipment requirements, and is not suitable for industrial applications. Zhou Bo proposed to use the method of twice sulfurization and dechlorination to treat sulfurized isobutylene containing chlorine atoms. This method simplifies the process steps and saves costs, but the production cycle is long.
Qi Xiangyang proposed to recycle the sulfur-containing waste liquid produced by the second-step sulfurization and dechlorination reaction and use it for the next first-step sulfurization and dechlorination reaction, which not only reduces the discharge of waste liquid, but also saves production costs. The new synthesis process solves the "three wastes" problem and reduces production costs, but the equipment investment is large, the production cycle is long, and the operation process is complicated, making it difficult to realize industrial applications.