STUDIES ON WATER-ABSORPTION OF EPOXY-RESI NS BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY

Electrochemical impedance spectra were measured for the aluminum elect rodes coated with epoxy resin films of various different crosslinking densities in 0.5 mol/L NaCl solution(room temperature) at open circuit potential, By fitting the Nyquist curves with the equivalent circuit generally used for the coated electrode, the values of the film resist ance, the film capacitance, the electrochemical reaction resistance an d the double layer capacitance were obtained and used to discuss the r elationship between the structure and the water absorption of epoxy re sins. It is found that the amount of the water absorbed in the cured e poxy resins increases with increasing extent of cure.