金属离子对不溶性硫磺稳定性的影响

Effect of Metal Ions on Stability of Insoluble Sulfur

针对不溶性硫磺在存储及使用过程中易还原为可溶性硫磺的问题,通过稳定剂筛选及性能评价,确定了其最佳加量;同时考察了不同稳定剂之间的协同作用,探讨了过渡金属离子对不溶性硫磺的稳定性以及对稳定剂稳定效果的影响。实验结果表明:金属离子存在下,不溶性硫磺的稳定性变差,金属离子d轨道平均电子空穴数越多对不溶性硫磺稳定性的影响越明显,稳定率下降幅度越大。单剂稳定效果以实验室合成黄原酸酯类稳定剂(DXD)、二硫化二异丙基黄原酸酯(DIP)、吗啉-4-二硫代甲酸-4-吗啉酯(OTOS)的稳定性较好,稳定率均可达75%,其中DXD可达80%。稳定剂复配实验表明,复配后的不溶性硫磺稳定剂的稳定效率均较单剂下降,其中以DIP与DXD复配体系的稳定率下降最明显;向稳定性较好的单剂及复配组合中分别加入铜离子及铅离子,结果表明铜离子配位能力较好,可与OTOS、顺丁烯二酸酐配位使稳定率有所提高,铅离子的存在会使稳定剂的稳定率呈下降趋势。

The insoluble sulfur in the storage and use process is easy to be reduced into soluble sulfur.In view of this,the various stabilizers had been screened and were valued in this paper,then the optimum adding amount was determined.At the same time,the synergistic effect was investigated in the mix process of different types of stabilizer.Then the effect of the transition metal ions on the stability of insoluble sulfur and on the stable effect of other stabilizers was also discussed.The experimental results showed that the stability of insoluble sulfur became bad in the presence of metal ions.In addition,the more the number of average electron holes in the d orbital of metal ions was,the more significant the effect on the stable rate of insoluble sulfur was,the bigger the deceasing degree of stability of insoluble sulfur became.Single agent experimental results showed that the stability of DXD,DIP,OTOS was better than any others.Their stable rates could reach 75%and the optimal DXD was up to 80%.Compound effect indicated that the stable rate of the insoluble sulfur after using compounded stabilizer deceased,compared with single agent effect.Among them,the decline of stability in the DIP and DXD complex system was the most.When the copper ion and lead ion were respectively added to the single-agent and compounded stabilizer with better stability,the results showed that the complexing ability of copper ions was better,it could complex with OTOS,maleic anhydride,thus the stability of insoluble sulfur was improved.And when lead ion was added,the stable rate of stabilizer showed a downward trend.