Hyperbranched grafting on oxidized polyethylene surfaces

A new method to prepare functional grafts on polyethylene is described. In this chemistry, a terminally functionalized poly(tert-butyl acrylate) is first attached to an oxidized polyethylene film. Subsequent hydrolysis of the tert-butyl esters at room temperature then produces a film with some poly(acrylic acid) grafts. Although this initial graft is present at low density, repetition of this process through 2-4 more cycles produces a heavily grafted polyethylene that exhibits much of the same chemistry seen for hyperbranched poly(acrylic acid) grafts on more defined inorganic surfaces. The resulting grafts are more effective platforms for further ionic modification of polyethylene than simple oxidized polyethylene.