Polyurethane/functionalized-graphene nanocomposite films with enhanced weather resistance and gas barrier properties

Abstract This study explores the potential of graphene for improvement of weather resistance and helium gas barrier properties of thermoplastic polyurethane (PU) film. PU/functionalized-graphene nanocomposite (PGN) films were produced by solution master-batching and subsequent melt mixing, followed by compression molding, with varying concentrations (0–3 wt%) of graphene, which resulted in uniform dispersion and partial exfoliation of graphene-sheets in PU matrix. The helium gas barrier of nanocomposite films improved gradually with increasing graphene concentration, showing about 30% reduction in gas-permeability at 3 wt% graphene-loading. The tensile strength and stiffness of the nanocomposite films also increased significantly with increasing concentration of graphene. The prepared PGN films were exposed to accelerated artificial weathering conditions up to 300 h. Due to excellent UV absorption capability of graphene, the weather resistance of nanocomposite films improved significantly, resulting in lower photooxidative and carbonyl index. Best weather resistance in terms of retention in tensile and gas barrier properties was obtained with 2–3 wt% of graphene.