不同动态载荷模式下交联网络结构对丁苯橡胶疲劳行为的影响

Effect of Dynamic Loading Mode on Fatigue Behavior of Styrene-Butadiene Rubber with Different Crosslink Types and Densities

以非结晶型丁苯橡胶(SBR)为基体,改变过氧化二异丙苯(DCP)及硫磺(S)用量制备了不同交联键类型和交联密度的SBR硫化胶,分别考察其拉伸、屈挠和压缩3种载荷模式下材料的疲劳寿命和破坏方式,研究不同载荷模式对SBR疲劳行为的影响。结果表明,不同载荷模式下含不同交联键的硫化胶疲劳行为以及最终破坏方式存在差异,交联密度低,对延长拉伸疲劳寿命更为有利。同时发现,碳碳交联键硫化胶的拉伸和压缩疲劳寿命都相对更短,但其耐裂纹增长能力优异。

The unfilled styrene butadiene rubbers(SBR) with different amounts of dicumyl peroxide(DCP) and sulfur(S) were fabricated, which have different crosslink bond types and crosslink densities. The fatigue life and failure mode of the materials under the three loading modes of tension, compression and flexion were investigated. And the influence of different loading modes on the fatigue behavior of SBR was studied. The results show that there are differences in the fatigue behavior and final failure modes of different vulcanization systems under different load modes. A low crosslink density is more beneficial to extend the tensile fatigue life, while a high crosslink density is beneficial to improve the compression fatigue life. At the same time, it is found that the tensile and compressive fatigue life of carbon-carbon cross-linked vulcanizates are relatively shorter, but their crack growth resistance is more excellent.