Effect of number of –CF3 groups in tails of polyester on surface wettability of coatings: synthesis and characterization of PFPE based polyesters with three -CF3 groups in tails

Toward the Replacement of Long-Chain Perfluoroalkyl Compounds: Perfluoropolyether-Based Low Surface Energy Grafted Nanocoatings

“…To this end, PFPE-based (co)­polymers, oligomers, and cross-linked materials were demonstrated in our preceding works and those of others to have the capability to serve as hydrophobic/lyophobic materials and interfaces. ,− ,− However, to the best of our knowledge, grafting of PFPE-based oligomers to an inorganic surface to obtain low surface energy nanocoatings, decreasing the spreading of oil and water, has not yet been reported in the scientific literature. With this in mind, we fabricated nanocoatings obtained through the grafting of PFPE-based polyesters.…”

“…Thus, for the fabrication of oil-repellent surfaces, fluorocarbon groups (−CF 2 and −CF 3 ) are used since they reduce the surface tension of the materials more than hydrocarbons do (CF 3 < CF 2 H < CF 2 < CH 3 < CH 2 ). − For decades, long-chain perfluoroalkyl compounds (C n F 2n+1 –, n ≥ 7, LCPFAs) have been used to obtain water- and oil-repellent surfaces in a number of applications, including membranes and polymer films, as well as surfactants. ,,− However, LCPFAs (frequently mentioned as ″forever chemicals″ in popular media), owing to their bioaccumulative and toxicological effect on the environment, humans, and wildlife, have been phased out of production and applications. − Currently, low surface energy perfluoropolyethers (PFPEs) are being considered as the replacement for long-chain perfluoroalkyl substances because of the presence of oxygen between the fluorinated units in their backbone. ,,,− Perfluoropolyethers are projected to be safer than LCPFAs because of the materials’ low toxicity and high oxidative/thermal stability. ,− PFPEs are biocompatible and present on the FDA list for food contact products . In addition, during the thermal degradation, PFPEs release in the environment significantly fewer compounds in comparison with other fluoropolymers …”

Effect of the Composition of Copolymers Based on Glycidyl Methacrylate and Fluoroalkyl Methacrylates on the Free Energy and Lyophilic Properties of the Modified Surface

“…The Young equation shows that the surface energy of the substrate is the greatest contributor to the increase in hydrophobic properties for the same surface topology; the lower the surface energy of the substrate, the greater the contact angle [ 30 ]. The lowest surface energy is known to correspond to compounds with alkyl and fluoroalkyl substituents [ 31 , 32 ]. For example, for polytetrafluoroethylene, it is approximately 19–21 mN/m [ 33 , 34 ], and for perfluoroalkylacrylates (with long perfluorinated substituents), it is approximately 10–12 mN/m [ 35 ].…”

Towards a Long-Chain Perfluoroalkyl Replacement: Water and Oil Repellent Perfluoropolyether-Based Polyurethane Oligomers

“…To this end, perfluoropolyether derived (co)polymers and cross-linked materials have been shown in our previous works and that of others to have the ability to serve as hydrophobic/lyophobic materials and interfaces [ 20 , 21 , 22 , 23 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. In particular, we have found that when PFPE-based triblock polyesters [ 20 , 21 , 37 ] or methacrylic molecular brushes [ 36 ] are added to engineering thermoplastic (PET, nylon 6, or polymethyl methacrylate) films, they readily migrate to the film surface, imparting significant water and oil repellency to the thermoplastic boundary. Specifically, the macromolecular additives populated the boundary with PFPE segments terminated with C 4 F 9 -perfluoroalkyl moiety, which cannot yield unsafe long-chain perfluoroalkyl carboxylic acids.…”