Yang Liu, Wang Lin, Guo Huaiqing, Du Aihua
Key Lab of Rubber-Plastics, Ministry of Education, Qingdao University of Science & Technology, Qingdao 266042, China.
Polymers (Basel). 2021 May 6;13(9):1497. doi: 10.3390/polym13091497.
The influence of carbon black on physical mechanical properties, compressive fatigue life, and the temperature changes during compression fatigue process of styrene-butadiene rubber (SBR) vulcanizates were explored. A series of unfilled and filled SBR compounds were prepared, and the compressive fatigue behaviors of the vulcanizates were performed on a mechanical testing and simulation (MTS) machine. The top surfaces of the filled SBR were imaged using scanning electron microscopy (SEM) after 105 cycles of compressive fatigue. The filled SBR shows greater compressive fatigue resistance than the unfilled SBR. The incorporation of carbon black into SBR improves the creep resistance. The best compressive fatigue resistance for the filled SBR was achieved by the addition of 30 phr carbon black. With the increase of carbon black content, the energy dissipation and the heat build-up increase simultaneously. Furthermore, SEM images of the vulcanizates suggest that the crack propagation mechanism of the unfilled and the filled SBR was different. For the unfilled SBR, due to periodical compressive stress, the polymer chains can be destroyed, and the cracks can be easily initiated and propagated, showing serious damage on the top surfaces of the specimen. However, for the filled SBR, the carbon black agglomeration around the cracks can greatly delay the generation of the cracks, decrease the fatigue damage, and ultimately improve the fatigue resistance.
研究了炭黑对丁苯橡胶（SBR）硫化胶的物理机械性能、压缩疲劳寿命以及压缩疲劳过程中温度变化的影响。制备了一系列未填充和填充炭黑的SBR胶料，并在机械测试与模拟（MTS）试验机上对硫化胶进行了压缩疲劳性能测试。在进行105次压缩疲劳循环后，使用扫描电子显微镜（SEM）对填充炭黑的SBR的顶面进行成像。填充炭黑的SBR比未填充炭黑的SBR表现出更强的抗压缩疲劳性能。在SBR中加入炭黑可提高其抗蠕变性。加入30份炭黑时，填充炭黑的SBR获得了最佳的抗压缩疲劳性能。随着炭黑含量的增加，能量耗散和生热同时增加。此外，硫化胶的SEM图像表明，未填充和填充炭黑的SBR的裂纹扩展机制不同。对于未填充炭黑的SBR，由于周期性压缩应力，聚合物链可能被破坏，裂纹容易萌生和扩展，在试样顶面上显示出严重损伤。然而，对于填充炭黑的SBR，裂纹周围的炭黑团聚可大大延迟裂纹的产生，减少疲劳损伤，并最终提高抗疲劳性能。
