TECHNOLOGY FOCUS - POLYMERS - Preferred Components: In the photovoltaic module backsheet (B1), the backbone of the compatible adhesive polymer in the first and second fluoropolymer coatings is selected from acrylic, urethane, aliphatic polyester, polyester urethane, acrylamide, urea and polycarbonate backbones (preferably a functional acrylic polymer). The compatible adhesion-promoting polymer is an amine functional acrylic polymer. The functional groups on the first and second surfaces of the polyester film are selected from carboxylic acid, sulfonic acid, aziridine, amine, isocyanate, melamine, epoxy, hydroxy, and/or anhydride. The photovoltaic module backsheet (B1) comprises first and second primers on the respective first and second surfaces of the polyester film, where the first and second primers provide the functional groups on the first and second surfaces of the polyester film that interact with the adhesive polymer to promote bonding of the first and second fluoropolymer coatings to the respective first and second surfaces of the polyester film. The first and second primers comprise a polymer selected from polyallylamine/melamine polymer, polyethylene imine polymer, ethylene acrylic acid copolymer, and acid modified polyolefin. At least one of the first and second primers is an acid or anhydride functional thermoplastic polymer that is coextruded with the polyester film. The first and second fluoropolymer coatings each have a thickness of about 0.1-2 mils. The first and second fluoropolymer coatings each comprise platelet-shaped barrier particles having an average particle size of 10-200 microns. The first and second fluoropolymer coatings each comprise platelet-shaped barrier particles (0.5-10 wt.%) based on total dry weight of the fluoropolymer in each fluoropolymer coating. The fluoropolymer of the first and second fluoropolymer coatings is selected from homopolymers and copolymers of vinyl fluoride comprising at least 60 mole% vinyl fluoride and homopolymers and copolymers of vinylidene fluoride comprising at least 60 mole% vinylidene fluoride. The fluoropolymer of the first and second fluoropolymer coatings comprises 1-40 wt.% of the compatible adhesive polymer based on fluoropolymer solids content. The polyester film has a thickness of about 0.5-10 mils. EXAMPLE - No suitable example given.