【摘要】 针对丁腈橡胶(NBR)材料密封性能的退化预测问题,提出了基于橡胶宏观力学性能变化与分子链断裂、交联等微观机理相关联的数学模型。利用Kinetics动态状态转移模型,选择氧化交联和大分子断链为两个主要微观缺陷,采用缺陷状态的混合产生模式表征橡胶静态宏观力学性能衰退趋势,建立了NBR老化模型。利用NBR热氧加速老化试验得到的不同温度下压缩永久变形保持率退化数据,通过对比现有橡胶退化模型验证了基于所建橡胶老化模型的有效性。基于缺陷状态转移的橡胶性能老化建模过程为橡胶性能老化分析提供了一种新方法,有利于各类橡胶老化寿命的评估研究。更多还原

【Abstract】 In this study,a mathematical model was proposed based on the correlation between mechanical property and microscopic ageing mechanisms of nitrile butadiene rubber( NBR) material,in order to predict the performance change of NBR sealing during ageing process. Oxidative cross-linking and molecular chain scission were two main microscopic mechanisms,which could induce performance degradation of NBR. The degradation trend of mechanical property was revealed by Kinetics model considering both mechanisms. And then the thermal-oxidative ageing model of NBR was developed for seal service life evaluation. Compression set of NBR was obtained by thermal-oxidative accelerated ageing tests at different temperatures. The results showed that,NBR ageing model based on the Kine-tics model was effective compared with the current ageing model for rubber.The modeling process associated mechanical property with microscopic ageing mechanisms was a new approach for ageing analysis of rubber,which would be used for ageing life evaluation of all rubbers.更多还原