Soluble hyperbranched grafts on polyethylene surfaces

Abstract

Here we report two methods to synthesize hyperbranched poly(acrylic acid) grafts on polyethylene films and powders. The previously reported route using α,[]-diaminopoly(tert-butyl acrylate) was repeated and all previous results were confirmed. This reaffirmed that we are able to grow substantial amounts of carboxylic acids on a polymer surface through repetitious grafting cycles. We then began to explore another route to the same hyperbranched surface product. This method employs a ceric ion initiator and relies on an aqueous solution of reagents for the selective modification of polyethylene surfaces. Analytical data determined that this streamlined method grew more dense carboxylic acid groups on the surface than the a,[]-diaminopoly(tert-butyl acrylate) route at comparable grafting stages. The ceric ion method is also reported to work with several monomers to produce a random hyperbranched copolymer covalently bound to a polyethylene surface.