两种超临界流体中废旧轮胎橡胶脱硫研究

Study on Devulcanization of Waste Tire Rubber in Two Supercritical Fluids

本文采用超临界二氧化碳和超临界乙醇作为废旧轮胎胎侧胶脱硫的反应溶剂,对比分析了反应温度对两种脱硫过程的影响,并且通过表观反应动力学研究了两个反应过程的差异。结果表明,超临界二氧化碳脱硫过程中,凝胶交联密度会随反应温度的升高逐渐增大,而超临界乙醇中脱硫凝胶交联密度更低。超临界二氧化碳脱硫过程有效反应温度更低,具有更小的反应活化能;超临界乙醇脱硫溶胶分子量更大,凝胶交联密度更小。

Supercritical carbon dioxide and supercritical ethanol were selected as the reaction solvent for the devulcanization of the waste tire sidewall rubber. The effects of reaction temperature on the two devulcanization processes were compared and analyzed. Apparent reaction kinetics was used to investigate the difference between the two reaction processes. The results showed that the gel crosslinking density will gradually increase with the increase of the reaction temperature in the supercritical carbon dioxide,while the gel crosslinking density was lower in the supercritical ethanol.The devulcanization in supercritical carbon dioxide showed the lower reaction temperature and smaller reaction activation energy. The sol from devulcanization in supercritical ethanol had the larger molecular weight and smaller crosslink density of gel.