人工气候老化对热塑性弹性体SBS结构与性能的影响

利用紫外老化试验箱,对热塑性弹性体SBS进行人工加速老化实验,采用色度计、显微镜、傅里叶变换红外光谱仪和力学试验机研究人工气候老化对SBS的颜色、表面形貌、显微结构和力学性能的影响.结果表明:随着老化时间的延长,SBS表面颜色逐渐变黄,裂纹逐渐变密,有羰基>CO生成,试样的断裂强度、扯断伸长率和撕裂强度先迅速降低,然后趋于稳定;而邵氏硬度随老化时间逐渐增大;其力学性能向硬而脆的方向发展;扯断伸长率变化幅度是检测降解变化的最明显指标.

Effects of artificial weathering on the structure and mechanical properties of thermoplastic elastomer SBS

Artificial accelerated weathering test on thermoplastic elastomer SBS was conducted by using a fluorescent UV/condensation weathering device.The changes in surface color,morphology,structure and mechanical properties were monitored by spectrometer,microscope,Fourier transform infrared spectroscopy and tensile testing machine.The results showed that the surface color of SBS turned to yellow with increasing aging time,and the cracks became dense gradually.Carbonyl(>CO) group was observed from ATR FTIR spectrum.The elongation at break,tensile stress at break and tear strength decreased quickly in the initial stage of aging procedure and then stabilized,while the Shore A hardness increased with the increase of aging time.The mechanical properties turned to be hard and brickle with the evolvement of aging.The change of elongation at break can be used to detect the degradation of SBS.