Cryogenic adhesives

Long, R.L., Cryogenic adhesive application. Papers from the Structural Adhesive Bonding Conference Presented March 15-16, 1966, NASA Marshall Space Flight Center, Clearinghouse for Federal Scientific and Technical Information, 1966. 

Table 10.3 Comparison of Tough Cryogenic Adhesives at Liquid-Hydrogen and Ambient Temperatures ...

The National Bureau of Standards at Boidder, Colorado, has prepared an excellent survey for NASA on available reports and publications on cryogenic adhesives and sealants."""... 

Williamson, F.R. and N.A. Olien, Cryogenic Adhesives and Sealants— Abstracted Publications, NASA 5P-3101, prepared for the Aerospace Safety Research and Data Institute, NASA-Lewis Research Center, 1977. 

Further, these materials exhibit a high energy absorption and high sound-dampening properties. These properties are retained under cryogenic conditions. However, in general, adhesion of UHMWPE to substrates is poor, even when the suiface is roughened. 

The foam head created when beer is poured or dispensed, is an important aspect of consumer approval of a particular beer product. Compared with champagne foams, beer foams need to have different properties and be much more stable (beer foam needs to last for about five minutes). A cryogenic electron microscope image of beer foam is provided by Wilson [73]. Consumer preferences for beer foams vary, but can be characterized in terms of foam stability, quantity, lacing (adhesion to a glass surface), whiteness, creaminess (bubble texture), and concentration [852,853], As a result, much work has been done in order to be able to control these properties. 

A silicone rubber adhesive layer is used in US-A-4081819 to bond an HgCdTe substrate, which includes an epitaxial layer, to a second substrate. The silicone rubber adhesive reduces the risk that the substrate cracks when cooled to cryogenic temperatures. 

The adhesive s thermal conductivity is important in minimizing transient stresses during cooling. This is why thinner bond thickness and adhesives or sealants with higher levels of thermal conductivity generally have better cryogenic properties. 

It is necessary that the adhesive retain some resiliency if the thermal expansion coefficients of the adhesive and adherend cannot be closely matched. At room temperature, a standard low-modulus adhesive may readily relieve stress concentration by deformation. At cryogenic temperatures, however, the modulus of elasticity may increase to a point where the adhesive can no longer effectively release the concentrated stresses. At low service temperatures, the difference in thermal expansion is very important, especially since the elastic modulus of the adhesive generally decreases with falling temperature. 

Advantages Highest shear strength in cryogenic range Uniform properties moderate cost RT cure easy handling low cost Adhesion to many materials easy handling... 

McClintock, R. M., and Hiza, M. J., Epoxy Resins as Cryogenic Structural Adhesives, Modem Plastics, June 1958. 

ESR has been used to investigate the role of the filler-matrix Interaction in filled rubbers at cryogenic temperatures (10). The breakdown In adhesion between filler and matrix results In vacuoles or voids in the material. Figures 3 and 4 show a contrast In behavior for Sp glass spheres In rubber with and without a silicone coupling agent treatment. In the first case strength Is low and very few free radicals are produced... 

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