Bouaziz Rami, Truffault Laurianne, Borisov Rouslan, Ovalle Cristian, Laiarinandrasana Lucien, Miquelard-Garnier Guillaume, Fayolle Bruno
Centre des Matériaux, Mines ParisTech, PSL University, CNRS UMR 7633 BP 87, F-91003 Evry, France.
PIMM, Arts et Metiers Institute of Technology, CNRS, Cnam, HESAM University, 151 boulevard de l'Hôpital, 75013 Paris, France.
Polymers (Basel). 2020 Oct 14;12(10):2354. doi: 10.3390/polym12102354.
Being able to predict the lifetime of elastomers is fundamental for many industrial applications. The evolution of both tensile and compression behavior of unfilled and filled neoprene rubbers was studied over time for different ageing conditions (70 °C, 80 °C and 90 °C). While Young's modulus increased with ageing, the bulk modulus remained almost constant, leading to a slight decrease in the Poisson's ratio with ageing, especially for the filled rubbers. This evolution of Poisson's ratio with ageing is often neglected in the literature where a constant value of 0.5 is almost always assumed. Moreover, the elongation at break decreased, all these phenomena having a similar activation energy (~80 kJ/mol) assuming an Arrhenius or pseudo-Arrhenius behavior. Using simple scaling arguments from rubber elasticity theory, it is possible to relate quantitatively Young's modulus and elongation at break for all ageing conditions, while an empirical relation can correlate Young's modulus and hardness shore A. This suggests the crosslink density evolution during ageing is the main factor that drives the mechanical properties. It is then possible to predict the lifetime of elastomers usually based on an elongation at break criterion with a simple hardness shore measurement.
能够预测弹性体的使用寿命对于许多工业应用而言至关重要。针对不同的老化条件（70°C、80°C和90°C），研究了未填充和填充氯丁橡胶的拉伸和压缩行为随时间的演变。随着老化，杨氏模量增加，而体积模量几乎保持不变，导致泊松比随老化略有下降，尤其是对于填充橡胶。在文献中，泊松比随老化的这种演变常常被忽视，其中几乎总是假设其恒定值为0.5。此外，断裂伸长率降低，假设为阿仑尼乌斯或伪阿仑尼乌斯行为时，所有这些现象都具有相似的活化能（约80 kJ/mol）。利用橡胶弹性理论中的简单比例论证，对于所有老化条件，都可以定量地关联杨氏模量和断裂伸长率，而经验关系可以将杨氏模量与邵氏A硬度相关联。这表明老化过程中交联密度的演变是驱动机械性能的主要因素。然后，通常可以基于断裂伸长率标准并通过简单的邵氏硬度测量来预测弹性体的使用寿命。
