废旧橡胶热-机械剪切脱硫过程及机理

利用元素分析仪、红外光谱仪研究了废旧橡胶热-机械剪切脱硫过程及其机理。在未加任何脱硫剂的情况下,利用双螺杆挤出机提供的热能和强剪切作用对硫化橡胶进行了脱硫回收,研究发现,硫化橡胶的交联密度下降到71%,恢复了再加工性能,并且微观结构也发生了显著的变化。提出了交联硫键断裂后以活性硫侧挂基形式存在的理论,解释了再生胶脱硫后不需外加硫磺仍可以硫化的现象。溶胶的红外光谱给这一理论提供了有力的证明。根据脱硫反应前后官能团的变化推测出脱硫反应可能的机理。

Mechanism of Thermal-Mechanical Shearing Devulcanization of Waste Rubber

The process and mechanism of thermal-mechanical shearing devulcanization of waste rubber were studied using elemental analyzer and FT-IR.It is found that with the action of strong mechanical shearing and the heat during the processing of the twin-screw extruder,the cross link rubber was devulcanized without any desulfurization.The crossing density dropped to 71%,and the waster recovered the process ability.Moreover,the microstructure of reclaimed rubber was changed obviously.A theory was proposed that the active graft sulfur chains have been formed when cross-bonds were ruptured.This theory can explains why the reclaimed rubber can still be vulcanized without adding the sulfur.The infrared spectra of the gel support this theory with a powerful proof.According to the changes of function groups,the possible mechanism of devulcanization reaction was speculated.