Perfluoropolyether-based oleophobic additives: Influence of molecular weight distribution on wettability of polyethylene terephthalate films

Abstract

Abstract Fluorinated oligomeric polyester (FOP) with significantly different molecular weight distributions were synthesized for use as surface-active additives to alter the wettability of polyester films. Specifically, FOPs had different weight average molecular weight (MW) of 5.4 and 10 kDA. The addition of FOPs in polyethylene terephthalate (PET) in different concentrations results in reducing the surface energy of PET/FOPs films. The PET/FOP film surfaces enriched with FOPs exhibited high water and oil repellency. It is found that not only concentration of FOPs in blends but also their MW influences wettability of PET/FOP film surfaces. The highest values of water and oil repellency were obtained when we used either low concentrations of low MW fluorinated polyesters that migrated to the surface easily, thus higher surface coverage were obtained, or high concentrations of higher MWpolyesters in the blends.