Study On Production Technology Of Insoluble Sulphur

Sulfur homopolymer is scientific name of insoluble sulfur referred to IS.It is an excellent vulcanizing agent in the rubber industry. It has become an exclusively vulcanizing agent for production of meridional tyre. In this paper, through the use of Chongqing Hynes insoluble sulfur coarse products, the optimal extraction conditions were experimentally derived. Insoluble sulfur content may available up to more than 95% on the condition of room temperature, extraction time 30min, the proportion of 6:1 of carbon disulfide volume and the insoluble sulfur quality.In the experiment of oil-treated, not only the effect of oil-treated proportion, the oil-treating time, the treating temperature and the yield of insoluble sulfur, but also the effect of basic nitrogen content of oils on the thermal stability of IS were studied. The results indicated that the nitrogen removed oil made thermal stability of IS increased more than 10% comparing with the pre-denitrogenation oil. The oil of different basic nitrogen contents were used in the experiments. It was revealed that the best amount of basic nitrogen concentration should be below 20μg/g when the thermal stability of IS was increased.The insoluble sulfur is a metastable substance and has poor high-temperature stability after the extraction of insoluble sulfur. In the thesis, in order to improve the thermal stability of IS the variety of chemical agents were used in oil-treating process. The effects of the type and the amount of stabilizer were studied in the oil-treating process of insoluble sulfur.When it was used singly as a stabilizer,influence of the type and the amount of stabilizer on thermal stability of IS was discussed. The oil-treating results between using the nitrongen unremoved oil and the nitrongen removed oils were compared. The results of the experiment showed that Phenolic antioxidants, the esters stabilizing agent, acid substances and turpentine made the thermal stability of IS enhanced. The IS stability of using nitrongen removed oil was higher than the nitrongen unremoved oil. Oleic acid can make the thermal stability of insoluble sulfur up to 95.54 percent by using the nitrongen removed oil. But alkaline substances made the thermal stability of IS reduced. T551, and tetraethylenepentamine made insoluble sulfur melted under the temperature of 105℃. So the basic material is detrimeatal to the thermal stability of IS.The effect of diffent compound stabilizers on the thermal stability of IS was discussed. The experimental results showed that two different steric phenolic antioxidant compounded the thermal stability of IS can up to more than 91%.By the aged testing of end-product, the results showed that processed with stabilizer the content of insoluble sulfur dropped only less than 4% after 90min at 80℃, on the contratry, the IS of products dropped 13.3 percent without stabilizer processed.