少量不同填料对炭黑/丁苯橡胶复合材料抗疲劳破坏性能的影响及其机理

Effect of a small amount of different fillers on fatigue resistance of carbon black/styrene-butadiene rubber composites and its mechanism

对于炭黑/丁苯橡胶复合材料,用5份白炭黑、黏土和淀粉分别等量替代炭黑,研究了复合材料在宽广应变范围(30%～100%)的疲劳破坏性能。结果表明,30%应变下,加入黏土胶料的疲劳寿命提高了1倍;100%应变下,加入白炭黑胶料的疲劳寿命提高了1倍;加入淀粉胶料的疲劳寿命下降。原因是由于在30%的应变下,加入黏土提高了复合材料的滞后能,而生热不大,且片层状黏土对裂纹扩展有较强的阻碍作用;加入白炭黑胶料的滞后能不变,由于白炭黑的粒径小于炭黑,抗裂纹能力提高,因而在所研究的应变范围内其抗疲劳破坏性能提高;由于淀粉的粒径是微米级的,且加入淀粉后复合材料的滞后能降低,因此其抗疲劳破坏性能降低。

The fatigue resistance of carbon black/ styrene-butadiene rubber composite was studied in a wide strain range（30% - 100% ） with 5 phr silica, clay and starch replacing the same amount of carbon black, respectively. The results showed that at 30% strain, the fatigue life of clay/carbon black/styrene- butadiene rubber doubled, at 100% strain, the fa- tigue life of silica/carbon black/styrene-butadiene rubber doubled, but the fatigue life of starch/carbon black/styrene-butadiene rubber reduced. The reason was： at 30% strain, adding clay improved the hys- teresis energy, but the heat build up was little, and the lamellar clay had an ability of impeding crack; although adding silica did not change the hysteresis energy, the crack resistance improved because the silica size was smaller than that of carbon black, so that the fatigue resistance improved in the studied strain range; adding starch reduced the hysteresis energy, which led to a poor fatigue resistance owing to the micron size of starch particles.