polüformaldehüüd

Polyformaldehyde, also known as polyoxymethylene (POM) or acetal, is a high-strength, stiff engineering thermoplastic. It is produced through the polymerization of formaldehyde. POM is known for its excellent mechanical properties, including high tensile strength, stiffness, and impact resistance. It also exhibits good dimensional stability and low moisture absorption, making it suitable for applications requiring precise tolerances. Furthermore, polyformaldehyde possesses good wear resistance and a low coefficient of friction, which contributes to its utility in moving parts. It is also resistant to a wide range of solvents and fuels.

The production of polyformaldehyde typically involves the polymerization of formaldehyde or trioxane, which is a cyclic trimer of formaldehyde. This process can be carried out cationically or anionically. The resulting polymer chains are primarily composed of repeating -CH2-O- units. POM exists in two main forms: homopolymers and copolymers. Homopolymers, such as Delrin, are made solely from formaldehyde and are generally harder and stiffer. Copolymers incorporate small amounts of comonomers, like ethylene oxide, which improve thermal stability and processing characteristics.

Polyformaldehyde finds widespread use in various industries due to its advantageous properties. It is commonly employed in the automotive sector for components like fuel system parts, seat belt mechanisms, and window regulators. In the electronics industry, it is used for connectors, switches, and gears. Consumer goods also utilize POM for items such as zippers, buckles, and appliance parts. Its ease of processing, including injection molding and extrusion, further contributes to its popularity.