Heat-resistant adhesives aerospace industry

Heat-Resistant Adhesives (Chapter 4), studies high-performance adhesives which display high heat resistance and are used in aerospace, aircraft construction, and we believe these adhesives will be used soon in other industries such as automotive, adhesives for mechanics, abrasives and industrial equipment. 

Epoxy-nitrile Nitrile-epoxy adhesives are composed of solid epoxy resin modified with carboxyl-terminated butadiene nitrile (CTBN) copolymer. The CBTN is introduced into die epoxy resin at elevated temperatures. The modification provides toughness and high peel strength without sacrificing heat and chemical resistance. The film adhesives are widely used in the aerospace industry in the construction of jetliners. 

As mentioned earlier, the growth of interest in high-temperature-resistant polymers has been mainly due to the need for these materials as adhesives and composites by the aerospace industry. But the utilization of heat-resistant polymers has been limited by the fact that these materials are often insoluble and infusible and therefore difficult to process. Hence, research during the past two decades has been mainly directed not towards attaining higher thermal stability, but towards the retention of as much stability as possible while introducing solubility or moldability (processibil-ity). It is this aspect of high-temperature polymers which is discussed in the next section. 

Epoxies have historically been the major adhesive family used for the structural bonding of metals and composites in the aerospace, industrial and automotive industries. They are characterised by curing to hard infusible resins that bond to a wide range of metals and have excellent resistance to heat and the environment. Epoxies have been used since the 1940s and have an excellent track record of successful structural bonding. Two-component and heat-cured one-component versions are available and literally thousands of formulations have been developed over the years for specific applications. 

Heat resistant and chemically resistant coating materials are attractive for applications in the automotive, aircraft and other industries. Guerriero et al. (2011) reported that coatings made of liquid crystal thermosetting polymers (LCT) showed markedly increased interface adhesion between LCT and an aluminum alloy substrate. Compared to a commercial LCP the LCT possessed higher hardness and stiffness, and this was favorable for their wear resistance. They concluded that LCTs have potential to serve as protective coatings for aerospace applications. 

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