Estimation of the surface free energy of polymers

A method for measuring the surface energy of solids and for resolving the surface energy into contributions from dispersion and dipole‐hydrogen bonding forces has been developed. It is based on the measurement of contact angles with water and methylene iodide. Good agreement has been obtained with the more laborious γ c method. Evidence for a finite value of liquid‐solid interfacial tension at zero contact angle is presented. The method is especially applicable to the surface characterization of polymers.