低温熔融法制备不溶性硫

在低温熔融法制备不溶性硫的过程中,考察了聚合温度,反应时间,稳定剂种类和加量,引发剂加量等因素对不溶性硫收率的影响,并采用正交实验获得了不溶性硫制备的优化条件,即稳定剂KI用量0.60%,引发剂过硫酸铵加量为0.40%,反应温度240℃,聚合时间45min,IS收率可达到44.02%。通过因素水平曲线表明影响不溶性硫收率的最主要因素是引发剂加量,其次是稳定剂用量。指出了要提高不溶性硫收率,应在严格控制反应温度、时间的前提下,进一步寻找性能优异的稳定剂和引发体系;同时在液硫反应之后急冷步骤可研发高压液硫喷嘴和急冷液循环分离系统,以助于液硫快速冷却,终止硫链断裂及环化反应,提高IS收率。

Preparation of insoluble sulphur by low-temperature melt

Low temperature melting preparation of insoluble sulfur(IS) was studied.The effects of polymerization temperature,reaction time,stabilizer type and dosage,and initiator dosage on IS yield were investigated,and the optimum parameters for IS preparation were determined by orthogonal tests.Under the conditions of stabilizer KI dosage of 0.60%,initiator(NH4)2S2O8 dosage of 0.40%,reaction temperature of 240℃ and reaction time of 45 min,the yield of IS was up to 44.02%.The factor level curves showed that the most important factor which influenced IS yield was initiator dosage,followed by stabilizer dosage.It was pointed out that in order to improve the yield of IS,it will need to find and use the stabilizer and initiator with higher performance besides controlling reaction temperature and time strictly,and high-pressure liquid sulfur nozzle and quenching medium circulation and separation sys-tem could be developed to rapidly cool the liquid sulfur particles in the quenching medium to terminate sulfur chain break reaction and cyclization and therefore to increase the yield of IS.