Application of atmospheric pressure plasma for adhesion improvement in polyurethane coating on polypropylene fabrics

Abstract

Atmospheric pressure plasma treatment modifies the surface of textile materials at nano level. The effectiveness of plasma surface modification is closely associated with fabric weave construction and surface structure. Adhesion properties of three different polypropylene (PP) fabrics with a polyurethane (PU) coating have been investigated with respect to different plasma treatment time and power. Peel off strength was measured as the separation force required to separate coating layer from fabric. Statistical analysis of the peel off strength was performed by ANOVA. A substantial increase in adhesion of PU on plasma-treated samples was observed. Various characterization techniques such as contact angle, X-ray photoelectron spectroscopy, scanning electron microscopy and tensile measurement were used to inspect hydrophilicity, surface chemistry, surface morphology and physical properties of PP fabrics, respectively. As evident from results captured using various characterization techniques, atmospheric pressure plasma treatment enhances the surface properties (hydprophilicity, surface morophology and surface chemistry) without affecting the bulk (tensile strength) properties. It is shown that the plasma treatment parameters as well as the textile structure play an important role in adhesion improvement. Further, it is observed that the effectiveness of the plasma treatment is closely linked to the structure of the textiles fabrics.