Adhesion modification of polyolefin surfaces with sodium hypochlorite in acidic media

Increased surface adhesiveness of HDPE is achieved by immersing it in an aqueous solution of sodium hypochlorite (bleach) mixed with an acid. This process results in the addition of functionality to the polymer surface vastly altering its adhesive, polarity and surface reactivity. Analysis of the modified polymer surfaces by ESCA has shown that chlorine atoms have been added to the surface. Studies regarding the chlorination of small molecules have also shown that the chlorination process is amenable to a variety of chlorination objectives and offers a route toward the functionalization of a variety of polymeric and non-polymeric substrates. In particular, this treatment renders unpaintable substrates such as HDPE more receptive to application of paints and adhesives. In this paper, we report the results of paint adhesion studies on treated polymer surfaces.