Fenolformaldehyde

Phenol formaldehyde is a thermosetting polymer, also known as Bakelite or Novolac. It is formed by the reaction of phenol with formaldehyde, typically under acidic or basic conditions. This reaction creates a cross-linked network structure, which gives the material its characteristic rigidity and thermal stability.

The polymerization process can be controlled to produce different types of resins. Resols, formed under alkaline conditions, contain methylol groups and can cure upon heating without the need for an additional curing agent. Novolacs, formed under acidic conditions, require a curing agent, usually hexamethylenetetramine, to cross-link.

Phenol formaldehyde resins exhibit excellent electrical insulation properties, good heat resistance, and mechanical strength. They are also resistant to many chemicals and solvents. However, they can be brittle and are not typically used in applications requiring high impact resistance.

Historically, phenol formaldehyde was one of the first synthetic plastics to be mass-produced and found widespread use in electrical components, automotive parts, and household goods like handles and housings. While its use has declined in some areas due to the development of newer polymers, it remains relevant in applications where its specific properties, such as excellent insulation and heat resistance, are critical.