芳纶纤维对炭黑/丁苯橡胶复合材料疲劳行为的影响
Influence of aramid fiber on the fatigue performance of carbon black/styrene butadiene rubber composites

使用短芳纶纤维（AF）增强炭黑/丁苯橡胶（CB/SBR）复合材料，研究AF对复合材料疲劳行为的影响。在应力控制条件下，少量AF的加入使缺口试样的疲劳寿命提高了25.5倍；疲劳使试样的储能模量（G'）降低，AF的加入使疲劳后试样的Payne效应降低，G0'/G100'值降低10.5%；复数模量随疲劳周期增加而降低，但少量纤维能使复合材料的复数模量保持在较高的水平，30 000周疲劳下AF-CB/SBR的复数模量仍为CB/SBR的1.73倍；疲劳后AF-CB/SBR复合材料的100%和300%定伸应力随疲劳变形量的增加而先增大后降低，断裂伸长率有所下降。试样疲劳后相对于拉伸变形量，纤维的增强作用产生滞后效应，相对界面滑脱能随疲劳应变幅度的增加而降低； SEM结果显示，疲劳后橡胶基体出现一定的剥离，纤维与橡胶界面受到损伤。 The influences of aramid fiber (AF) on the fatigue behavior of AF reinforced styrene butadiene rubber filled with carbon black composites (AF-CB/SBR) were researched. Under the stress control condition, the fatigue life of notched specimens can be improved 25.5 times with the help of the addition of a small amount of AF. The storage modulus of the rubber samples decreases after the fatigue process and AF in this system can decrease the ratio of G0' and G100' (G0'/G100') to 10.5%, indicating lower Payne effect compared with the one without AF. The complex modulus decreases with the increase of fatigue cycles, while higher complex modulus can be remained in the composites which contain a small amount of AF than the one without AF. The complex modulus of AF-CB/SBR composite was 1.73 times as that of CB/SBR system even if the fatigue cycles have reached to 30000. The stretching stress at 100% and 300% of fatigued sample increases first and then reduces with the increasing of fatigue progress, while the elongation at break decreases. Relative to the deformation, fiber reinforcement has a hysteresis effect, and the relative interfacial slip energy decreases with the increase of fatigue strain amplitude; SEM photos exhibite a certain extent stripping of the rubber matrix and the interface between fiber and rubber is destroyed after the fatigue process. 黔科合重大专项（2013—2016）；国家自然科学基金（51761004）