| Résumé : |
"Adhesives are social substances", writes Irving Skiest, author of Handbook of Adhesives. "They unite materials, creating a whole that is greater than the sum of parts." Adhesives bond similar or dissimilar substrates, and growth in the adhesives industry has emanated from its advantages over other joining methods. For an adhesive to bond two substrates, it must: a) wet the substrate, b) chemically bond with the substrate, and c) have good cohesive strength. It is sometimes necessary to incorporate additives to wet the surface and bond with the substrate.
Keep in mind that adhesion is not a property of a material; it depends on many factors, including substrates (mainly the surface, not bulk), surface preparation, adhesive type (chemistry), specimen geometry (joint design), test method and environment. In the case of bonding zinc-coated steel with aluminum, for example, it is the aluminum and zinc surfaces that have to bond, not the steel.
Due to the growing concern over the toxicity of organo-mercury compounds in the environment, there is a universal effort to replace mercury-containing polyurethane (PU) adhesives. Organo-mercury compounds are used as catalysts in PU adhesives. The PU adhesives described in this paper represent 100% solid, two-component (2K) systems. |
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Ajouter le résultat dans votre panier Affiner la rechercheMercury-free polyurethane adhesives in ADHESIVES & SEALANTS INDUSTRY (ASI), Vol. 17, N° 7 (07/2010)
