Abstract: Using independently designed single screw extruder, ground tire rubber (GTR) powder was devulcanized continuously to prepare devulcanized ground tire rubber (DGTR). The DGTR was further revulcanized to prepare revulcanized DGTR samples. The gel fractions of the DGTR and the crosslink densities of the revulcanized DGTR samples decreased and the tensile strengths and elogations at break of the revulcanized DGTR samples increased gradually with increasing screw speed. The best devulcanization effectiveness was achieved under 40 r·min^-1 screw speed and 205℃ devulcanization temperature. The revulcanized DGTR sample prepared under this condition exhibited tensile strength and elogation at break of about 11 MPa and 386% respectively. Inferring from the Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses, parts of S—S and C—S bonds in the GTR powder were broken under both shearing and heating in the independently designed single screw extruder.

Key words: ground tire rubber powder, regeneration, devulcanization, extrusion, preparation, structure and properties

摘要： 利用本课题组研制的单螺杆挤出机,对废旧轮胎胶(GTR)粉进行连续脱硫制备再生胶(DGTR),并对DGTR进行再硫化制成DGTR硫化试样.结果显示,随螺杆转速增加,DGTR凝胶含量和DGTR硫化试样交联密度逐渐降低,DGTR硫化试样的拉伸强度和拉断伸长率有所提高;螺杆转速设定为40 r·min^-1时,在205℃脱硫温度下取得了最好的脱硫效果,DGTR硫化试样的拉伸强度和拉断伸长率分别约为11 MPa和386%.从红外光谱和光电子能谱的分析结果推测,在单螺杆挤出机的剪切和热等的共同作用下,GTR粉中部分S—S键和C—S键发生了断裂.

关键词: 废旧轮胎胶粉, 再生, 脱硫, 挤出, 制备, 结构与性能