| Insoluble sulfur is a product obtained by ring-opening polymerization of common sulfur,and is currently mainly used as a special curing agent for radial tires.Domestic insoluble sulfur is currently synthesized by high-temperature gasification.This method has high conversion rate but harsh production conditions,poor product high-temperature stability,and the crushing process of insoluble sulfur is prone to explosion.In this paper,the low-temperature melting method is used to synthesize crude insoluble sulfur,the polymerization,quenching,and solidification processes are researched,and the influence of wet pulverization and extraction process conditions on the quality of insoluble sulfur is explored,and stabilizers are added to the extractant and filler oil.To improve the high temperature stability of IS.By measuring the change of the viscosity of the insoluble sulfur system with temperature,it is concluded that the viscosity of the IS system reaches the maximum at 260℃,and this is used as the basis for the selection of the reaction temperature for the low-temperature synthesis of IS.The single-factor method is used to conduct the low-temperature synthesis of insoluble sulfur.After investigation,the experiment found that the optimal process conditions are: polymerization temperature 260℃,polymerization time 1h,quenching liquid uses deionized water,quenching temperature is room temperature,curing temperature 50℃,curing time 4h,IS yield under this process condition is 35.00%.By adding water as the pulverizing medium during the pulverization process,dust explosion can be avoided during pulverization.By comparing the property difference and pulverization effect of deionized water and tap water,it is found that the salt content and acid content of deionized water are lower than tap water.Its IS content and stability are higher than tap water pulverization,so deionized water is selected as the pulverization medium.This article also investigated the repeated use of deionized water and found that as the number of repeated uses increases,the IS content and stability decrease,so fresh deionized water should be replaced in time.It is also found that the content of the pulverized IS powder decreases as the immersion time in water is prolonged,and the stability first decreases and then increases.Therefore,to obtain a high-content and high-stability IS product,suction filtration should be performed immediately after pulverization.In this paper,carbon disulfide is used as the extractant,and the best extraction stage for error flow extraction is three.The countercurrent extraction effect is better than the cross flow extraction,and the amount of extractant can be reduced to save costs.The experiment shows that the optimal extraction conditions for three-stage cross-flow extraction are: extraction temperature is room temperature,extraction time is 30 minutes,and extractant sulfur ratio is10:1.Adding a proper amount of stabilizer in the extraction and oil-filling process can improve the thermal stability of IS,and when the stabilizer is added in the extraction and oil-filling process at the same time,the effect of improving the stability of IS is better.When the oil is extended without a stabilizer,3% stabilizer C is added as a stabilizer during extraction,the stability of IS at 105℃ can reach 85.47%,and the stability at 120℃ can reach51.16%;when no stabilizer is added in the extraction stage,the stability of IS can reach85.47%.Add 3% stabilizer B as stabilizer in the oil stage,IS 105℃ stability can reach83.34%,120℃ stability reaches 45.57%;when 3% stabilizer C is added to the extractant and2% stabilizer is added to the filler oil When A is used as a stabilizer,the stability of IS is the highest,with a stability of 92.4% at 105℃ and a stability of 54.11% at 120℃. |
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