Optimization of sodium dodecyl sulphate loading in poly(vinyl alcohol)-water coatings

A residual solvent study in poly(vinyl alcohol)-water based system has been carried out. The effect of anionic surfactant sodium dodecyl sulphate on the drying behavior of coatings was investigated. Attempts were made to optimize the surfactant loading in order to minimize the residual solvent and drying time. Surfactant loadings were changed from 0.5% to 2.5% by weight. The residual solvent left was 5.88%, 4.88%, 4.17%, 3.85%, 3.27%, and 2.54%, in coatings having 0%, 0.5%, 1%, 1.5%, 2.0%, and 2.5% SDS, respectively. The effect of initial coating thickness on the residual solvent was also investigated. The optimum surfactant loading comes out to be independent of the initial coating thickness.