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Polyoxymethylene (POM) Materials
“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.
It was discovered by Hermann Staudinger, a German chemist who received the 1953 Nobel Prize in Chemistry. He studied the polymerization and structure of POM in the 1920s to research the theory of macromolecules, which he characterized as polymers. Due to initial problems with thermal stability, POM was not commercialized.
First synthesized by DuPont research chemists around 1952, the company filed for patent protection of the homopolymer in 1956. DuPont credits R. N. MacDonald as the inventor of high molecular weight POM. Patents by MacDonald and coworkers describe the preparation of high molecular weight hemiacetal (~CH2OH) terminated POM, but these lack sufficient thermal stability to be commercially viable products. The inventor of a useful POM homopolymer was Dal Nagore, who discovered that reacting the hemiacetal ends with acetic anhydride converts the readily depolymerizable hemiacetal into a thermally stable, melt processable plastic. DuPont completed construction of a plant to produce Delrin at Parkersburg, West Virginia, in 1960. Celanese completed its study on a copolymer in 1960, producing Celcon in 1962 and Hostaform in 1963 in Kelsterbach, Germany, under a limited partnership with Ticona.”
(Wikipedia, Polyoxymethylene, 5/4/2012)
“The preparation of polyoxymethylenes ("POM") is known per se. For example, cyclic oligomers of formaldehyde, such as 1,3,5-trioxane ("trioxane") or tetraoxocane, are polymerized with the aid of cationic initiators. The polymerization can be effected both in the mass as precipitation polymerization and in the melt under pressure. After polymerization is complete, the active chain ends are deactivated by addition of basic compounds. “[Haubs et al, US Patent 8,133,966 (3/13/2012)]
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These pages list the links as they are found. Some will abstracted and added to Maro Topics. (RDC 2/7/2012)
Roger D. Corneliussen
Maro Polymer Links
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Copyright 2012 by Roger D. Corneliussen.
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* Date of latest addition; date of first entry is 5/4/2012.