丁腈橡胶/有机小分子共混物阻尼材料热稳定性研究

The study of nitrile rubber/organic small molecule blending on the heat stability

针对丁腈橡胶NBR/有机小分子AO-2 246共混物阻尼材料热稳定性欠佳的现象,借助动态力学分析仪(DMA)、红外光谱(FT-IR)、X射线衍射(XRD)以及扫描电镜(SEM)等表征手段对其机理进行了研究。结果表明,高含量有机小分子AO-2 246的NBR/AO-2 246共混物,阻尼性能优异,但其稳定性欠佳。随着退火温度的提高,阻尼性能下降与材料内部氢键逐渐消失有关,而氢键的消失会导致大量结晶体的产生,结晶体进一步对阻尼材料阻尼性能产生不利影响。在SEM微观形貌中发现,晶体易于沿着材料内部界面处优先生成,这归因于界面效应。随着退火温度提高,发现晶体形貌也发生了变化,即晶体结构处于不稳定状态,这是氢键逐渐消失的结果。

The damping mechanism of the nitrile rubber （NBR）/organic small molecule AO-2 246 blending was investigated due to its poor thermal stability property.The dynamic mechanical analyzer （DMA）,Fourier transform infrared （FT-IR）,X-ray diffraction （XRD）,scanning electron microscope （SEM）,etc were used. The results showed that the NBR/AO-2 246 blending displayed an outstanding damping property but a poor heat endurance performance when there was a rich content of AO-2 246.With the increase of annealing temper-ature,a gradual decline in the damping capacity was apparently related to the disappeared of the hydrogen bond which could induce a large amount of crystals from AO-2 246.These crystals could further damage the damping performance.In this study,the results from SEM indicated crystals might be prone to generate on the internal interfaces attributed to the interface effect.It was found the crystal morphology was also changed with increas-ing annealing temperature,which indicated the crystal structure was unstable,resulting from the gradual disap-pearance of the hydrogen bond.