摘要
采用在熔融挤出过程中提高双螺杆挤出机螺杆转速的高剪切应力诱导方法,研究了双螺杆挤出机的螺杆转速、挤出反应温度和添加线性高分子材料品种对轮胎胶脱硫共混物(DGTR/EPDM)的凝胶含量、溶液特性黏数、溶胶分子链结构及再硫化材料力学性能的影响.结果表明:随着双螺杆挤出机螺杆转速的增加,强烈的剪切应力作用可引起轮胎胶粉中交联网络的断裂、降解反应,引起产物凝胶含量和溶胶特性黏数的明显下降;挤出反应温度越高,轮胎胶中交联网络的断裂、降解反应即越明显,产物凝胶含量和溶胶特性黏数的下降即越显著.采用具有较高门尼黏度的热塑性弹性体作为溶胀剂和承载流体时,可获得具有较高相对分子质量的脱硫共混物溶胶和较好力学性能的脱硫共混物共混丁苯橡胶再硫化材料.在220℃和1200 r/min的脱硫反应条件下,所得脱硫共混物共混丁苯橡胶再硫化材料的拉伸强度和断裂伸长率分别达到21.0 MPa和456%,分别达到丁苯生胶混炼胶硫化材料拉伸强度和断裂伸长率的87.5%和128%.
The effects of the high shear stress of twin screw extruder during melt extruding on the gel content and the sol intrinsic viscosity number of the devulcanized blends and FF-IR spectra of their sols were investigated by increasing the screw rotation speed and reaction temperature. The results show that the high shear stress of twin screw extruder can stress-induce the chain scission and degradation of the crosslinking network of the ground tire rubber, thus leading to the decrease of the gel content and the sol intrinsic viscosity number of the devulcanized blends, and the higher the screw rotation speed and the reaction temperature, the more obvious the chain scission and degradation of the cross-linking network. The mechanical properties of the revulcanized blends are obviously improved by using the linear polymer with a higher mooney viscosity. Under devulcanization conditions of 220 % and 1 200 r/min, the tensile strength and the elongation at break of the revlucanized blend are 21.0 MPa and 456%, respectively, and reach to 87.5% and 128% of the tensile strength and elongation at the break of vulcanized SBR, respectively.
出处
《南京工业大学学报（自然科学版）》
CAS
北大核心
2009年第3期74-80,共7页
Journal of Nanjing Tech University(Natural Science Edition)
