Sell Polyoxymethylene(POM)

详情

Polyoxymethylene (POM), also known as acetal, polyacetal and polyformaldehyde is an engineering thermoplastic used in precision parts that require high stiffness, low friction and excellent dimensional stability. As with many other synthetic polymers, it is produced by different chemical firms with slightly different formulas.

Properties
POM is characterized by its high strength, hardness and rigidity to ~*0 °C. POM is intrinsically opaque white, due to its high crystalline composition, but it is available in all colors. POM has a density of ρ = 1.****1.**0 g/cm3.
POM homopolymer is a semi-crystalline polymer (****5% crystalline) with a melting point of **5° Celsius. The POM copolymer has a slightly lower melting point of **2 – **3° Celsius.
POM is a tough material with a very low coefficient of friction. However, it is susceptible to polymer degradation catalyzed by acids, which is why both polymer types are stabilized. Both homopolymer and copolymer have chain end groups (introduced via end capping) which resist depolymerization. With the copolymer, the second unit normally is a C2 (ethylene glycol) or C4 (1,*-butanediol) unit, which is introduced via its cyclic acetal (which can be made from the diol and formaldehyde) or cyclic ether (e.g. ethylene oxide). These units resist chain cleavage, because the O-linkage is now no longer an acetal group, but an ether linkage, which is stable to hydrolysis. POM is sensitive to oxidation, and an anti-oxidant is normally added to molding grades of the material.

POM advantages:
High abrasion resistance
Low coefficient of friction
High heat resistance
Good electrical and dielectric properties
Low water absorption