Fenoolformaldehüüd

Fenoolformaldehüüd, also known as phenol formaldehyde resin, is a synthetic polymer that results from the reaction between phenol and formaldehyde. This reaction, often catalyzed by either acid or base, creates a thermosetting plastic that undergoes an irreversible curing process when heated.

The initial reaction produces a liquid or solid prepolymer, which can then be molded and heated to form a rigid, cross-linked network. This structure gives phenol formaldehyde resins their characteristic properties of high strength, heat resistance, electrical insulation, and chemical inertness. They are typically dark brown or black in color.

Phenol formaldehyde resins were among the first synthetic plastics to be commercially produced, with Bakelite being a famous early example developed by Leo Baekeland. Historically, they have been used in a wide variety of applications. These include electrical components like insulators and plugs, automotive parts, adhesives, coatings, and as binders in materials such as plywood, particleboard, and brake linings. They were also used in the production of billiard balls, radios, and camera bodies.

While still in use for certain specialized applications where their unique properties are advantageous, the use of phenol formaldehyde resins has declined in some areas due to concerns about the potential release of formaldehyde during processing and use, as well as the development of alternative materials. Recycling of cured phenol formaldehyde resins is also challenging due to their thermosetting nature.