Fatigue life of unfilled polychloroprene rubber is characterized in fully relaxing (R = 0) and non-relaxing conditions (R = 0.2) for more than 15 network structures. Network changes are induced by thermal oxidation ageing of the rubber and characterized especially in terms of crosslink density. For the first time, in the case of unfilled elastomers, we show that an increase in crosslink density leads to a decrease in fatigue life, which cannot be attributed to large changes in strain-induced crystallization processes. The results obtained here are used to determine the relationship between network structure and fatigue properties. In fully relaxing conditions, it is possible to predict fatigue lifetime by considering crosslink density using a theoretical energetic approach. Nevertheless, the same approach does not work in non-relaxing conditions. In the latter case, a new empirical relationship is proposed to link fatigue life to the crosslink density of rubber.

未填充 聚氯丁橡胶的疲劳寿命具有完全松弛（R =0）和非松弛条件（R = 0.2) 超过 15 个网络结构。网络变化是由橡胶的热氧化老化引起的，尤其是在交联密度方面。在未填充弹性体的情况下，我们首次表明交联密度的增加导致疲劳寿命的降低，这不能归因于应变诱导结晶过程的大变化。此处获得的结果用于确定网络结构与疲劳性能之间的关系。在完全松弛的条件下，可以通过使用理论能量方法考虑交联密度来预测疲劳寿命。然而，同样的方法在非松弛条件下不起作用。在后一种情况下，提出了一种新的经验关系，将疲劳寿命与橡胶的交联密度联系起来。