Aircraft metal bonding-nitrile phenolic

The thermosetting films are employed for metal-to-metal bonding in aircraft, as well as less demanding appliance, electrical, and automotive requirements. These adhesives are hybrids designed to provide an optimum combination of shear strength, elongation, and heat resistance. Nitrile-phenolic and epoxy-nitrile are the leaders, followed by vinyl butyral-phe-nolic, epoxy-nylon, and epoxy-phenolic. The nitrile rubber in the epoxy-nitrile is a carboxyl-terminated butadiene-nitrile polymer which reacts with the epoxy at the elevated cure temperature. 

Nitrile rubber/phenolic resin produces one of the most durable and toughest elastomeric materials developed in the adhesive industry. Further, its resistance to water as to organic solvents is excellent. For these reasons, the nitrile rubber/phenolic resin laminates are used in printed circuit board manufacturing, to bond metallic substrates between themselves (aluminium, steel) and to bond rubber to magnesium. Films of nitrile rubber/phenolic blends have also been used in the aircraft industry for bonding metal-to-metal surfaces in both plain and honeycomb sandwich constructions. 

NBR adhesives have excellent shelf stability and high temperature properties. They are used in aircraft, automobile, paper, and electronics applications. Blended with phenolic resins, they have been used to laminate aluminum and stainless steel, fabricate airplane structures, bond abrasives to metal, brake linings to brake shoes, laminate leather, attach soles in shoe manufacturing and bond cardboard, polymeric films, masonite, wood and metal to each other and themselves. Nitrile rubber-phenohc resin blends are poor adhesives for non polar elastomers such as natural rubber, butyl rubber, polyethylene unless their surfaces have been activated to improve adhesion. 

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