Phenolic resins are synthetic polymers formed as condensation products of phenols and aldehydes. This step-growth polymerization reaction can be either acid- or base-catalyzed. In acid, the reaction forms novolac resins. These resins require a curing agent - often hexamethylenetetramine or hexa. They are not heat-sensitive. In alkaline solution, the polymerization reaction produces resole resins. These resins are sensitive to heat and acids, do not require curing agents, and have relatively short shelf lives. Hexion scientists are constantly adding to the extensive family of Bakelite® resins by varying the reaction conditions and specific raw materials used. This formulation flexibility allows for an almost infinite number of modifications and products. In other words, by tweaking the formulas, our scientists optimize our resin products to fit our customers’ processing and performance specifications.