Cyanates industrial applications

Some industrial applications include the oxidation of cyanide with chlorine and ozone to cyanate. Ozone coupled with ultraviolet light is used to oxidize halogenated organic compounds, which are usually resistant to oxidation with ozone alone. 

TABLE 7. Organic cyanates and a nitrile oxide that found industrial application ... 

Our new approach has proven its initial value in both palladium-(Schareina et al. 2004) and copper-catalyzed cyanations (Schareina et al. 2005) and has been adopted by other groups. Very recently, in a joint collaboration with Saltigo GmbH we developed a new and improved copper-based catalyst system, which allows for efficient cyanations of a variety of aromatic and heteroaromatic halides. Importantly, notoriously difficult substrates react in excellent yield and selectivity, making the method applicable on an industrial scale. 

Redox electrodes are mainly used as sensors in processes involving redox couples. An important application is in the metal plating industries where cyanide has to be removed from the plant effluents. Cyanide is efiminated in alkaline solutions by oxidation with chlorine gas in the first step to cyanate ions and then continuing the oxidation process to produce nitrogen and carbon dioxide as the final products ... 

While the overall growth of composites in the aerospace industry is continuing, epoxy has been facing stiff competition from other materials and the growth rate has been relatively small (2% annually). While epoxies are still used in many exterior aircraft parts, carbon fiber composites based on bismaleimide and cyanate esters have shown better temperature and moisture resistance than epoxies in military aircaft applications. In the commercial aircraft arena, phenolic composites are now preferred for interior applications because of their lower heat release and smoke generation properties during fires. High performance thermoplastics, such as polysulfone, polyimides, and polyetherether ketone (PEEK), have also foimd some uses in aerospace composites. 

Densely cross-linked PCN networks, synthesized by polymerization, via cy-clotrimerization reaction, of dicyanic ester of bisphenol A [159-161], consist of rigid triazine heterocycles as junctions connected with bisphenol A remainders (see a scheme in Fig. 26). At the total conversion of cyanate groups (Xcn pcn 1). PCN exhibits high Tg 300°C and rigidity, good adhesion to different substrates and chemical resistance, as well as low values of dielectric constant and water uptake. This allowed in particular its application as the matrix for glass- and aramid fiber-reinforced plastics in the electronics and aerospace industries. 

Of these, apart from the amino-formaldehyde systems used on wooden structures, the aerospace industry currently concentrates on epoxies, phenolics and polyimides for the majority of its structural bonding applications it is the epoxies that are the real workhorse for the industry. Acrylic and polyurethane chemistries are used, but in very few applications of a structural nature. The relatively novel chemistry based on cyanate esters, for example Arocy B 10 (dicyanate ester of Bisphenol A) ... 

From these beginnings have come the commercial ranges of structural adhesives based, particularly, on phenolic, epoxy, polyimide (PI), and now cyanate ester chemistries that have been tailor-made for the various applications within the aircraft industry and, in the last few years, for space applications. These adhesives impart, as required, a combination of toughness, thermal resistance, and durability to the bonded joint. 

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