在废旧轮胎胶粉/EPDM的熔融挤出过程中,以仲丁醇为脱硫反应促进剂,研究螺杆转速和挤出反应温度对脱硫共混物凝胶质量分数(w)、凝胶分子链结构以及SBR/脱硫共混物再硫化材料物理性能的影响.结果表明:在废旧轮胎胶粉/EPDM的熔融挤出过程中,随着螺杆转速和挤出反应温度的升高,废旧轮胎胶粉颗粒所受的机械剪切应力作用增强,引起废旧轮胎胶粉中交联网络的断裂、降解或解交联反应,导致脱硫共混物w显著减小以及SBR/脱硫共混物再硫化材料中凝胶粒子尺寸明显减小；添加仲丁醇有利于脱硫反应的进行,并具有抑制交联副反应和保护脱硫产物中双键的作用,使脱硫共混物的w进一步减小;在螺杆转速为1 000r· min-1、挤出反应温度为240℃的条件下,SBR/脱硫共混物(添加仲丁醇)再硫化材料的拉伸强度和拉断伸长率分别为19.3 MPa和567％.%During melt extrusion of the mixture of ground tire rubber and EPDM,2-butyl alcohol was added as devulcanization accelerator,and the effect of screw rotating speed and reaction temperature on the gel content of devulcanized blends, molecular structure of gel and physical properties of SBR/devulcanized blends was investigated. The results showed that,as the screw rotating speed and reaction temperature increased during extrusion,the mechanical shear stress on ground tire rubber enhanced, which made cross-linking network break up, degrade or retro-crosslink, resulting in low gel content of devulcanized blends and small size of gel particles in SBR/devulcanized blends. By adding 2-butyl alcohol, the process of devulcanization was accelerated, side-reactions were restrained, double bonds were protected,and the gel content of devulcanized blends was further decreased. With the 2-bu-tyl alcohol accelerated devulcanization condition of screw rotating speed at 1 000 r · min-1 and reaction temperature at 240 ℃ ,the tensile strength and elongation at break of SBR/devulcanized blends were 19. 3 Mpa and 567% respectively.
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