Temperature dependence of contact angles on elastomers

Contact angle measurements with three different liquids were performed on: (i) butyl rubber PB 101‐3 (Polysar Ltd.) and (ii) Dow Corning 236 dispersion. Contact angles were measured at different temperatures within the range from 23°C (room temperature) to 120°C. The surface tensions, γ sv , of the polymeric coatings at each temperature were calculated from the contact angles. The temperature coefficients of the surface tensions, d γ sv / dT , i.e., the surface entropies, were established for the temperature range covered.