ABSTRACT
The effect of ageing elastomers under a pre-strain in the direction of the applied strain has been a well-investigated topic. The effect of this ageing in directions other than the applied strain has not been examined as much. In this work, the effect ageing nitrile butadiene rubber (NBR) samples at fixed strain on the stress-strain behavior including experiments into their anisotropy has been investigated and compared to predictions made using the dual-network theory. NBR sheets have been aged unstrained, in simple tension and pure shear at 125 °C for 24 hours. Small dog-bone cut-outs have been cut at different orientations including in the direction of strain and perpendicular to the direction of strain. These cutouts have then been tested in simple tension. The results have been compared between unaged samples, samples aged in tension and samples that have undergone ageing under no strain. This is done to identify the effects of the thermal ageing.
