ADSORPTION OF HYDRODISPERSIBLE POLYMERS ON PETP FILM - INFLUENCE ON THE DEWETTING OF POLYMERIC SOLUTIONS

In order to obtain homogenous polymeric coatings on PETP films, we hav e studied the dynamics of dewetting for thin films of polymeric soluti ons (hydrodispersible copolyester) as a function of the contact angle, theta, the viscosity, eta and the superficial tension, gamma. Measure ments are reported of the growth of dry patches studied by direct obse rvation and are correlated to the dewetting velocity V = k gamma theta 3/eta. A good agreement is obtained at short times. Nevertheless, at longer times, a convective and diffusive adsorption inhibites the dewe tting phenomenon.