Fluorinated coatings

G. Nickel. Nickel (nip 1,453°C), finds its primary use in the construction of apparatus to handle fluorine and volatile fluorides. In this situation the metal is rendered passive by a fluorine coating. Nickel plating is easily performed and provides a means of imparting corrosion resistance. The metal may be machined, silver soldered, copper brazed, or welded. However, the weld should be performed on clean surfaces because the presence of impurities containing lead, sulfur, phosphorus, and various low-melting metals leads to embrittlement and failure at the weld. 

The outdoor durability of a fluorinated coating is directly related to its fluorine content and is assessed by gloss retention [51],... 

This section does not cover the topic of coatings and finishes. These finishes are usually highly formulated and are applied as multiple-pass coatings which include special primers and intermediate layers. They may include pigments, additives, other resins, and more than one fluoropolymer. The main applications of fluoropolymer finishes are in cookware and industrial anticorrosion and high-temperature uses. A separate volume, Fluorinated Coatings and Finishes, a Plastics Design Library (PDL) volume in the Fluorine Handbook Series published by William Andrew, Inc., covers the topic. 

The first two books of the series cover commercial fluoropolymers (ethylinic) the third book focuses on their applications in the chemical processing industries. The fourth book deals with fluoroelastomers, the fifth with fluorinated coatings and finishes, and the sixth book is about fluorinated ionomers such as Nafion . 

The reason why only the fluorinated ester drops spread over one of the fluorinated coatings can be explained by mutual attraction promoted by the structural and chemical affinity of the two fluorine-containing organic compounds. It had been established [5] that the fluorinated side chains of polymer S are sterically less closely packed and have more freedom of rotation than those of polymer A they may thus permit some lateral penetration of the closely related fluoro chains of the glutarate ester, whereas polymer A with its tight array of side chains is impervious to such penetration. The fluorinated ester exerts a slight solvent action on polymer S, but not on polymer A, when the polymer is totally immersed in the ester for periods longer than 10 days at ambient temperature, or 2 days at 50°C. 

Reports of new materials and formulations and resin properties are prolific. Articles of a topical or applied interest include probes for in-situ hardness measurements on adhesives, photobase generators for image recording devices, oxygen inhibition in packaging applications, resins for sign boards, potentiometric sensors, new photodefinable polyimides, visible curable resists, " clay composites, putties, silica fillers, curable paints, soluble photocurable systems, fluorinated coatings and in-... 

Hence, the high effectiveness of fluorinated coatings is associated with their ability to lower the critical surface tension, Yc of the treated surface well below that of any fluid other than a fluorocarbon (Rao and Baker, 1994). It is worth recalling that the lower the Yc of a solid surface. 

The next contribution is Behaviour of FluorochemicaTTreated Fabric in Contact with Water by Dr Ana Robert Estelrich (Pymag, S.A., Spain). The introduction of fluorinated coatings in the textile industry has improved significantly the hydro- and... 

Witte JD, Piessens G, Dams R (1994) Fluorochemical intermediates, surfactants and their use in coatings. Fluorine Coat., Int. Conf., Paper 17... 

Katsikogianni M, et al. Adhesion of slime producing Staphylococcus epidermidis strains to PVC and diamond-like carbon/silver/fluorinated coatings. J Mater Sci Mater Med 2006 17(8) 679-89. 

Substitution of fluorine by alkoxy and aryloxy groups occurs especially easily (Scheme 12). Thus, 4-(l-naphthoxy)trifluorophthalonitrile was obtained upon treatment of TFPN with equimolar amount of sodium 1-naphtolate in methanol at room temperature (71 %) [26], Reaction of TFPN with 1-adamantanol (1 2 ratio) in the presence of BuLi in THF affords 4,5-diadamantyloxy substituted dinitrile (RT, 76 %) [27], All fluorine atoms are substituted when TFPN is heated with alcohols or phenols in DMF in the presence of K2CO3 as a base [27-29], In such way, among others tetrakis(2,2,2-trifluoroethoxy)- and tetrakis(2,2,3,3,3-pentafluoropropoxy) phthalodinitriles 50a and 50b (yields >90 %) - the precursors for the fluorine-coated phthalocyanines were obtained [28, 29]. 

McKeen LW. Fluorinated Coatings and Finishes, William. Norwich, NY Puh/Elsevier 2006. 

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