SURFACE ACTIVITY OF FLUORINATED ORGANIC COMPOUNDS AT ORGANIC-LIQUID/AIR INTERFACES. PART V - THE EFFECT OF PARTIALLY FLOURINATED ADDITIVES ON THE WETTABILITY OF SOLID POLYMERS,

The surface properties of polymeric solids have been successfully modified by the adsorption of appropriate fluorinated compounds at polymerair interfaces during the formation of the polymer surfaces. It was found that certain fluorocarbon derivatives would adsorb at polymerair interfaces when added directly to the monomer before polymerization or when placed in a solution of the polymer, in which case the polymer surface was formed by the slow evaporation of the solvent. As expected, the amount of adsorption in either case was found to be dependent upon the organophilicorganophobic blance in the solute, which depends upon its fluorine content, molecular structure, and solubility in the bulk polymer phase. The surface activity of the fluorinated compounds at each polymerair interface was determined from the changes in wettability of the smooth, solid polymer surfaces brought about by their adsorption. It was demonstrated that additives developed previously to be surface active in organic liquids markedly decreased the critical surface tension of wetting gamma sub C of polymer surfaces. Author