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,G_0′/G_(100)′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 G（100）′（G0′/G（100）′）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.