phenolformaldehyd
Phenol-formaldehyde, commonly called phenolic resin, is a class of synthetic thermosetting polymers obtained by condensation of phenol with formaldehyde. Depending on the phenol/formaldehyde ratio and catalysts, PF resins are mainly divided into novolacs and resoles. Novolacs are phenol-rich, require a separate curing agent to crosslink, and are used in adhesives and high-temperature laminates. Resoles are methylolated or otherwise prepolymerized to contain reactive groups and can cure upon heating without an external hardener, forming a rigid network when heated in the presence of acid or base catalysts.
Chemistry and processing: The condensation produces methylene and ether bridges between phenol units. The curing step
History and uses: The first commercial PF resin, commonly known as Bakelite, was developed by Leo Baekeland
Properties and safety: PF resins exhibit high thermal stability, flame resistance, and strong chemical resistance, along