poliformaldeídos

Poliformaldehídos, often shortened to polyacetals or POM, are a class of engineering thermoplastics. They are characterized by a high degree of crystallinity and are based on a polymer chain of repeating formaldehyde units. This structure results in a material with excellent mechanical properties, including high stiffness, strength, and impact resistance, even at low temperatures. POM also exhibits good dimensional stability, low friction, and excellent wear resistance, making it suitable for applications involving moving parts and demanding environments.

There are two main types of polyacetals: homopolymers and copolymers. Homopolymers, such as DuPont's Delrin, are made solely of formaldehyde units. Copolymers, like those produced by Celanese (Ultraform) or BASF (Ultraform), incorporate small amounts of comonomers, typically ethylene oxide or butanediol, which improve thermal and chemical stability. Both types can be processed using standard thermoplastic techniques like injection molding and extrusion. POM is resistant to a wide range of solvents and fuels, but it can be susceptible to strong acids and bases. Its applications are diverse, ranging from automotive components like fuel system parts and gears to consumer goods such as zippers and appliance parts, and industrial equipment like conveyor belts and bearings.