Influence of repellent finishing on the surface free energy of cellulosic textile substrates

The aim of this research is to investigate the influence of a fluorochemical repellent treatment with and without an added durable press finish on the surface free energy changes of a cellulosic textile substrate as well as the durability of the finishing agents. For this purpose, contact angles are measured based on the goniometric-sessile drop technique. Different theoretical models are chosen to calculate the solid surface free energy and its dispersive and polar components. A statistical evaluation of the results with ANOVA (P < 0.01) shows that the values of the surface free energy components of the finished textile substrate depend on a theoretical model as well as the chosen liquid combinations. Coating the textile substrate with fluoropolymer repellents alone and in combination with the durable press finish changes the highly hydrophilic polar cellulosic fabric into an almost apolar low energy solid. Laundering of the finished substrate in a surfactant aqueous solution decreases oil repellency, and a full rearrangement of the fluorocarbon polymer film on the textile surface is achieved after the heat treatment. What is also achieved is excellent durability of the fluoropolymer film on the textile substrate.