Network stability of FKM rubber compounds under hydrogen pressure.

Fluorocarbon-based rubber (FKM) compounds are typically utilized in the aeronautical industry due to its exceptional chemical and thermal resistance and recently has drawn significant interest from the hydrogen community for various hydrogen applications, but there exists little data evaluating its hydrogen compatibility. In this paper, a formulated FKM compound was exposed to ultrahigh hydrogen pressure (90 MPa) and analyzed by attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and crosslinking densities by solvent swelling measurement. ATR-FTIR spectroscopic data demonstrated that high-pressure hydrogen not only caused cleavages in polymer backbone and cross linkages, but also induced additional degradation of FKM compounds by breaking intermolecular hydrogen bonding between carboxylic acids, which were produced during rubber molding and post curing processes. This hydrogen pressure-driven degradation was significantly higher towards the core of the material than at the surface due to its weaker bonding between polymers and fillers. [ABSTRACT FROM AUTHOR]