Study On Non-ODS Substitute Solvent For Chlorinated Rubber Production

At present, most of domestic producers of chlorinated rubber(CR) use carbon tetrachloride(CTC) as process agent, which results in a large amount of CTC emission to the air. As an ozone depleting substance (ODS), application of CTC should be well controlled under the Montreal protocol. According to the national sector plan for ODS process agent application, CTC consumption as process agent will be completely phased out by 2010. However, CR product possesses important developing foreground and favorable market. Thus study and development on the substitute solvent for CR production is of great importance for China to fulfill the requirement of the Montreal Protocol to phase out CTC consumption and keep production of CR product in the future.This dissertation focuses on the study of non-ODS solvent substitute for CR production, process technology and novel production technologies. Regarding solvent substitute development, the chlorination reactivity of such solvents as Tetrachloroethene, 1,1,2,2-Tetrachloroethane, Petroleum ether, isopropyl alcohol, fluorobenzene, 1,3-Difluorobenzene, cyclohexane, chloroform, chlorobutane, n-Hexane and 1,2-dichloroethane has beenexperimentally studied, and the corresponding chlorinated solvents analyzed with gas chromatography. The results show that there are some difficulties in finding an ideal inert solvent to chlorine as substitute of CTC, however, some solvents that react with chlorine quite slowly may be chose as candidates of CTC substitute for the production of CR, e.g. fluorobenzene and dichloroethane.The production process of CR is studied by using fluorobenzene as substitute solvent, and the quality of CR product thus obtained is compared with that of traditional CTC solvent technology. The results show that the product quality is comparable except for the unpleasant odor of CR product made with fluorobenzene solvent. If the product odor can be removed, fluorobenzene may be used as a substitute solvent of CTC.Considering the facts that it is hard to achieve important breakthrough on development of solvent substitute technology in the near future, and aqueous phase technology is inevitably inhomogeneous, a semi-aqueous CR production process is proposed herein which posses the merits of both CTC solvent and aqueous phase technology. As we know the chlonnation reactions for both CTC solvent process and semi-aqueous phase technology are gas-liquid interfacial reaction, while for aqueous phase process it is a gas-solid interfacial chlorination, hence the chlorination uniformity of semi-aqueous phase is superior to aqueous process and similar to that of CTC solvent process. In addition, the viscosity of the reaction system for...