Diffusion in Multicomponent Polymeric Coatings

Several models have been developed to describe the diffusion transport in multicomponent polymeric coatings using Bearman''s friction factor theory. In this work, all the available models have been tested against measured concentrations at several depths and time in given coating using confocal laser Raman spectroscopy. Experimental results shows that none of the model is able to predict complete drying behavior of multicomponent polymeric coatings. A new method has been developed to find near optimum drying condition for binary coating. Method has been tested for multizone dryers. It needs only a drying code and obviates the need of optimization subroutine. Non-Fickian trasnport has been observed experimentaly and it is first work which shows experimental proof of non-Fickian drying in polymeric coatings which turns glassy at drying conditions.