Chemical compatibility of nitrile, EPDM and fluor elastomers for oil and gas applications

Abstract

The present study evaluated the chemical compatibility between six elastomers used in Oi & Gas applications and five fluids. The immersion tests had a duration of 8 weeks and the mass, volume and hardness of the elastomers were monitored along this time. Xylene was the most aggressive fluid overall, leading to mass variation of 100% in one case. EPDM was the most affected material, while the nitrile rubbers presented intermediate behavior and the fluorinated rubbers, the best performance. Moreover, FFKM was not significantly affected by any fluid. For better evaluation of the effects of the ageing, Compression Stress Relaxation tests were performed using the elastomers immersed in Xylene for 8 weeks. No difference on the slope of the curves of the unaged and aged samples was observed, but the ageing lead to increase in stiffness of the materials. FTIR was also performed aiming at identifying the chain modification of the materials immersed in Xylene, and only the fluorinated rubbers presented some small variations on the spectra.