Due to their good mechanical properties, low density, and ease of processing polymer nanocomposites are of interest for a multitude of applications in the automotive, electronics, and leisure industry. Besides having an impact on short-term mechanical performance of polymers, the addition of nanoreinforcements can have also a significant effect on long-term properties such as the resistance to static (creep) and cyclic (fatigue) loadings. However, despite its significance there is a shortage of long-term mechanical performance data for thermoplastic-based polymer nanocomposites. Reason being that existing characterization methods for long-term performance and durability are time consuming and limited in their applicability. Here, an engineering approach to predict long-term time-to-failure of polycarbonate/carbon nanotube (PC/CNT) nanocomposites is presented based on short-term experimentation with an application to both creep and fatigue. Results showed that the addition of CNTs had an opposite effect on two important long-term failure mechanisms. Addition of CNTs lead to improvements in durability in the plasticity-controlled failure regime, whereas it had an adverse effect in the slow crack growth-controlled regime, meaning that in the latter regime nanocomposite performance was significantly less than that of the neat polymer matrix.

由于其良好的机械性能，低密度和易于加工，聚合物纳米复合材料引起了汽车，电子和休闲行业的众多应用的兴趣。除了会影响聚合物的短期机械性能外，添加纳米增强材料还会对长期性能产生重大影响，例如对静态（蠕变）和循环（疲劳）载荷的抵抗力。然而，尽管它具有重要意义，但对于热塑性基聚合物纳米复合材料而言，缺乏长期的机械性能数据。原因是现有的用于长期性能和耐用性的表征方法既耗时又适用性有限。这里，基于短期实验，提出了一种预测聚碳酸酯/碳纳米管（PC / CNT）纳米复合材料长期失效时间的工程方法，并将其应用于蠕变和疲劳。结果表明，碳纳米管的添加对两个重要的长期失效机制具有相反的影响。碳纳米管的添加可提高可塑性控制的失效状态下的耐久性，而对缓慢裂纹扩展控制的状态则具有不利影响，这意味着在后一种状态下，纳米复合材料的性能明显低于纯聚合物基体。