resol resin

A resol is a fusible resin, soluble in alkali and alcohol, formed during the alkaline condensation of phenol and an aldehyde. It is essentially a mixture of phenol alcohols and represents the first resin stage in creating phenolic resins. These phenolic resins, like Bakelite, were the first fully synthetic polymers to be commercialized and revolutionized the market for molded and laminated parts, particularly for electrical equipment.12

Phenol-formaldehyde resins are still important industrial polymers, commonly used as adhesives for bonding wood products like plywood due to their moisture resistance and ability to form chemical bonds with lignin. In industrial processes, resol is produced by reacting an excess of formaldehyde with phenol using a base catalyst. This low-molecular-weight prepolymer can then be cured into a solid, thermosetting network polymer. Natural resins, often plant secretions, have largely been replaced by synthetic resins, which are categorized as either thermoplastic or thermosetting.23