用双螺杆挤出机脱硫制备再生胶的工艺及性能

Preparation process and properties of reclaimed rubber by twin screw extruder

利用改进的双螺杆挤出机对废旧轮胎橡胶胶粉进行剪切脱硫,讨论了螺杆转速和反应温度对脱硫效果及再生胶力学性能的影响,通过扫描电镜分析了胶粉脱硫前后形貌的变化及再生胶硫化试样的界面结合状况。结果表明,废旧轮胎橡胶胶粉的凝胶含量和交联密度随着螺杆转速和反应温度的升高明显下降,脱硫胶粉恢复了塑性,再生胶硫化试样的界面结合紧密。将螺杆转速控制在50～120 r/min、反应温度控制在190/180/170～210/190/200℃时脱硫效果最佳,此时再生胶的拉伸强度由未脱硫前的3.1 MPa提高到了12.4 MPa,扯断伸长率由75%提高到452%。

The waster tire rubber powder（WTRP） was devulcanizated by a reconstructed twin screw extruder.The effects of screw rotation speed and reaction temperature on devulcanization and mechanical properties of revulcanized rubber were investigated.The morphological change of WTRP before and after devulcanization and interfacial bond of reclaimed rubber vulcanizate were characterized by scanning electron microscope.The results showed that the crosslinking density and gel content of WTRP decreased remarkably with the increase of screw rotation speed and reaction temperature.The devulcanized WTRP recovered part of plasticity,and its vulcanizate had much better interfacial bond.Under the best devulcanization condition of screw rotation speed of 50-120 r/min and reaction temperature of 190/180/170 ℃-210/190/200 ℃,the tensile strength of the vulcanizate increased from 3.1 MPa to 12.4 MPa,the elongation at break increased from 75% to 452%.