Adhesion is the attachment of one material to another, due to a variety of potential interfaces. Adhesives are sticky substances that are commonly used to bind unlike molecules together. Adhesives have an altered molecular structure due to bonding between molecules to the substrate surface. Adhesion can work in three ways, molecules of a polymer may fill cracks in the surfaces being attached, the molecules may also develop attraction by intermolecular forces, or they may react by developing covalent bonds.
Cohesion is defined as the interior strength of an adhesive as an outcome of many variations of exchanges within the adhesive. Cohesive forces are the intermolecular forces which cause a predisposition in liquids to counterattack separation. These forces exist between molecules of the same substance. For instance, rain falls in droplets, because water has strong cohesion which pulls its molecules tightly together due to the slightly positive charge of one end of the droplet and the negative of the other. This force bonds molecules of liquids, gathering them into fairly large groups due to the molecules ' aversion for its surroundings.
In a typical adhesive, like liquid glue, monomer molecules and a stabilizer are in a solvent. The stabilizer discontinues the monomers from making a solid polymer. Interaction with the water in the air and on the surfaces being combined together by the glue lets the stabilizer become inactive. This lets the monomers merge to generate polymers. As more polymers are formed, the adhesive alternates from a liquid to a solid. Cohesive forces are forces which hold together the
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