Curing (chemistry) Curing (chemistry) Curing is a term in polymer chemistry and process engineering that refers to the toughening or hardening of a polymer material by cross-linking of polymer chains, brought about by electron beams, heat, or chemical additives. When the additives are activated by ultraviolet radiation, the process is called UV Cure. In rubber, the curing process is also called vulcanization. Five types of curing systems are in common use. They are: Despite the wide variety of thermoset resin formulations (epoxy, vinylester, polyester, etc.), their cure behavior is qualitatively identical. The resin viscosity drops initially upon the application of heat, passes
Extreme pressure additive pressure additives are rarely used in motor oils. The sulfur or chlorine compounds contained in them can react with water and combustion byproducts, forming acids that facilitate corrosion of the engine parts and bearings. Extreme pressure additives typically contain organic sulfur, phosphorus or chlorine compounds, including sulfur-phosphorus and sulfur-phosphorus-boron compounds, which chemically react with the metal surface under high pressure conditions. Under such conditions, small irregularities on the sliding surfaces cause localized flashes of high temperature (300-1000 °C), without significant increase of the average surface temperature. The chemical reaction between the additives and the surface is confined to this area.