Multiple hydrophilic polymer ultra-thin layers covalently anchored to polyethylene films

Abstract

A novel procedure has been developed to covalently graft multiple hydrophilic polymer ultra-thin layers to functionalized polyethylene surface. Polyethylene films have been functionalized by two methods, chromic acid oxidation and maleic anhydride grafting, to produce surfaces containing reactive groups, carboxylic acid and anhydride, respectively. The reactive groups formed in the functionalization were used to anchor a poly(vinyl alcohol) (PVA) ultra-thin layer by thermal esterification. After anchoring PVA, a second ultra-thin layer, constituted of poly(acrylic acid) (PAA), was also anchored. The second layer was anchored by thermal esterification between PVA hydroxyl groups and PAA carboxylic acid groups. The procedure presented in this work allows the formation of an ultra-thin layer. The macromolecule anchoring reactions occur only at the interfaces, consequently, only the macromolecules in contact with the interface are anchored. The formation of the ultra-thin layer and the surface characteristics have been analyzed through XPS, ATR-FTIR, SEM, and AFM data.