轮胎胶应力诱导脱硫及其对PP热塑性弹性体力学性能的影响

在轮胎胶粉熔融挤出过程中添加不同品种的热塑性弹性体作为溶胀剂和承载流体，并通过提高挤出机螺杆转速的高剪切应力诱导方法，研究了螺杆转速和挤出反应温度对脱硫轮胎胶共混物的凝胶含量、溶胶红外吸收光谱及聚丙烯（PP）/脱硫轮胎胶共混物热塑性弹性体力学性能的影响。结果表明，以乙烯-辛烯共聚物为承载流体时，所制备的PP动态交联热塑性弹性体的性能最好；仲丁醇、多烷基苯酚二硫化物或仲丁醇与多烷基苯酚二硫化物复合使用，均能促进脱硫反应的进行，并引起脱硫共混物中凝胶含量的减少、双键结构含量的增加和PP动态交联热塑性弹性体力学性能的明显增大；在转速为1000 r/min、温度为240 ℃的脱硫条件下，PP/脱硫轮胎胶共混物热塑性弹性体的拉伸强度和断裂伸长率分别达到11.2 MPa和123.2 %。

Devulcanization of Ground Tire Rubber Through High Stress-induced Reaction and Its Effect on Mechanical Properties of PP Dynamic Vulcanized Thermoplastics Elastomer

The devulcanization reaction of ground tire rubber (GTR) through melt extrusion was studied. When alkyl phenol disulfide and/or 2-butyl alcohol were used as promoter, the gel content in GTR was decreased, content of C=C double-bond in the sol was increased. After the devulcanization at 240 ℃ and 1000 r/min, GTR was blended with PP and POE forming a thermoplastic elastomer with a tensile strength of 11.2 MPa and an elongation at break of 123.2 %.