Use of ionic liquids in SECM experiments to distinguish effects of temperature and water in organic coating swelling

•The effect of temperature onto the organic coating swelling can be evaluated thanks to SECM experiments in RTIL.•However, this contribution is low when compared to the global organic coating swelling.•Obtained during hygrothermal ageings so water uptake appears then has the major effect to the global organic coating.•The global organic coating swelling is however higher than the sum of water effect and temperature effect.•The excess swelling was attributed to a relaxation of internal stresses.