Phenol formaldehyde resins (PF) are synthetic polymers obtained by the reaction of
phenol or substituted phenol with
formaldehyde. Used as the basis for
Bakelite, PFs were the first commercial synthetic resins (plastics). They have been widely used for the production of molded products including
billiard balls, laboratory countertops, and as coatings and
adhesives. They were at one time the primary material used for the production of
circuit boards but have been largely replaced with epoxy resins and
fiberglass cloth, as with fire-resistant
FR-4 circuit board materials.