木质素对SBS弹性体不同温度下热氧老化性能的影响

Effect of Lignin on Thermal Oxidation Aging Properties of Styrene-butadiene-styrene Block Copolymer Elastomer at Various Temperature

以苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）、玉米秸秆木质素为原料，以二氧六环为共溶剂，采用溶液浇铸的方法，制备了木质素填充的SBS弹性体膜材料。利用力学性能测试以及动态力学分析（DMA）、红外光谱分析和X射线光电子能谱（XPS）分析等方法，研究了木质素对SBS不同温度下热氧老化性能的影响。实验结果表明：在140-160℃温度范围内，老化2h后，木质素填充的SBS弹性体相比于未改性SBS拉伸强度的降幅由38．57％降至16．29％，断裂伸长率的降幅由35．96％降至8．30％；橡胶段玻璃化转变温度降幅由7．06％降至2．32％。木质素的添加有效减缓了高温热氧老化造成的SBS橡胶段玻璃化转变温度的变化以及SBS表面氧元素含量增加的幅度。木质素对SBS的填充起到了防老化的作用，提高了SBS的耐老化性能。

The styrene-butadiene-styrene block copolymer （SBS） membrane materials filled with corn straw lignin were prepared through solution casting. The effect of lignin on the thermal oxidation aging properties of SBS aged at various aging temperature for same aging time were studied by mechanical property testing, dynamic mechanical analysis （DMA）, infrared spectrum analysis （FTIR） and X-ray electron energy spectrum （XPS）. The experimental results showed that at the temperature range of 140-160℃, after aging for 2 hours, compared with the unmodified SBS, the tensile strength decreasing amplitude of the SBS elastomer modified with lignin had fallen from 38.57% to 16.29%, the elongation at break decreasing ampli- tude had declined from 35.96% to 8.30%, and the glass transition temperature decreasing amplitude of rubber segment dropped from 7.06% to 2.32%. Filling modification of SBS with lignin would effectively retard the change degree of the glass transition temperature of the rubber segment of SBS and increase the content of O element on the surface of SBS resulted by the thermal oxidation aging. Lignin filling modification of SBS has played an im- portant role in anti-aging, which improves the aging resistance of SBS.