滑动接枝共聚物/丁腈橡胶复合材料及其阻尼性能

Sliding graft copolymer/nitrile butadiene rubber composites and its damping property

  • 摘要: 将丁腈橡胶(NBR)与预硫化滑动接枝共聚物(SGC)混合制备SGC/NBR复合材料,并采用DSC、橡胶加工分析仪(RPA)、TEM和FTIR等研究了预硫化温度对复合材料内部结构及动态力学性能的影响。结果表明:SGC作为分散相在NBR基体中形成了海岛结构,且与NBR 大分子之间形成了分子间氢键,使两相相容性较好并形成了明显的界面作用区。界面作用区的存在使SGC/NBR复合材料的玻璃化转变温度与纯NBR基体相比升高,同时使复合材料的拉伸强度和拉断伸长率等力学性能显著增强,并出现了明显的拉伸取向。由于SGC与NBR之间分子链的扩散以及氢键作用,使分子链σ单键的内旋转受阻,旋转时需要消耗能量以克服所受的阻力,造成SGC/NBR复合材料的损耗因子明显增加,其中预硫化温度为160℃时阻尼效果最好。SGC/NBR复合材料在建筑桥梁振动频率应变变形范围内表现出优异的损耗性能,可应用于高阻尼隔震支座。

     

    Abstract: Sliding graft copolymer (SGC)/nitrile butadiene rubber (NBR) composites were prepared by blending NBR with presulfiding SGC. The effects of presulfiding temperature on internal structure and dynamic mechanical properties of the composites were investigated by DSC, rubber processing analyzer (RPA), TEM, FTIR, etc. The results show that the sea island structure forms:with SGC as the dispersed phase in NBR matrix. The intermolecular hydrogen bonds are formed between NBR macromolecule, leading to good compatibility and apparent interfacial interaction region. Compared with the pure NBR matrix, the glass transition temperature for SGC/NBR composites increase and the mechanical properties such as the tensile strength and elongation at break of composites increase significantly with stretch orientation because of the existence of the interfacial interaction region.Due to the diffusion and hydrogen bonding between SGC and NBR molecular chains, the internal rotation of the molecular chain σ single bond is hindered, so composites need to consume energy to overcome the resistance when rotating, resulting in significantly increase of loss factor. Especially, the damping property of composite with the SGC precured at 160℃ is best. The SGC/NBR composites exhibite excellent damping properties in the range of the vibration frequency and strain deformation of the building and could be expected to have important applications as a high damping seismic isolators.

     

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