Urea-formaldehyde

Urea-formaldehyde

Urea-formaldehyde, also known as urea-methanal, named so for its common synthesis pathway and overall structure [ [http://www.chm.bris.ac.uk/webprojects2002/robson/uses_of_formaldehyde.htm Uses Of Formaldehyde ] ] , is a transparent thermosetting resin or plastic, made from urea and formaldehyde heated in the presence of a mild base such as ammonia or pyridine. These resins are used in adhesives, finishes, MDF, and molded objects. Urea-formaldehyde resin's attributes include high tensile strength, flexural modulus and heat distortion temperature, low water absorption, mould, high surface hardness, elongation at break, and volume resistance.

Urea formaldehyde was commonly used when producing electrical appliances casing e.g. desk lamps. It is now mostly replaced by melamine resin.Fact|date=April 2007. Urea-formaldehyde foam insulation started being used in the 1950s. In the 1980s, concerns began to develop about the toxic formaldehyde vapor emitted in the curing process, as well as from the breakdown of old foam. Consequently, its use was discontinued. [http://www.nsc.org/EHC/indoor/formald.htm Environmental Health Center Formaldehyde FAQ]

Urea formaldehyde is also used in agriculture as a controlled release source of nitrogen fertilizer.Urea formaldehyde’s rate of decomposition into CO2 and NH3 is determined by the action of microbes found naturally in most soils. The activity of these microbes, and therefore the rate of nitrogen release, is temperature dependent. The optimum temperature for microbe activity is approximately 70°-90°F.

References

External links

* [http://www.plastiquarian.com/uf.htm Urea formaldehyde (Plastics Historical Society)]
* [http://www.cmhc-schl.gc.ca/en/co/maho/yohoyohe/inaiqu/inaiqu_008.cfm Urea-Formaldehyde Foam Insulation] (Canada Mortgage and Housing Corporation)
* [http://www.epa.gov/iaq/formalde.html#Levels%20in%20Homes Indoor Air Quality: Formaldehyde] (US Environmental Protection Agency)
* [http://www.hse.gov.uk/lau/lacs/37-9.htm UFFI] (UK Health and Safety Executive)


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  • urea-formaldehyde resin — [yo͞o rē′əfôr mal′də hīd΄, yoor′ē əfôr mal′də hīd΄] n. any of a class of strong, odorless, thermosetting resins formed by condensing urea and formaldehyde in the presence of a catalyst: used in making buttons, tableware, etc …   English World dictionary

  • urea–formaldehyde resin — ▪ chemical compound       any of a class of substances belonging to the family of organic polymers (polymer), prepared by heating urea and formaldehyde in the presence of mild alkalies, such as pyridine or ammonia. The urea and formaldehyde… …   Universalium

  • urea-formaldehyde resin — karbamidinė derva statusas T sritis chemija apibrėžtis Termoreaktyvusis oligomeras iš karbamido ir formaldehido. atitikmenys: angl. carbamide resin; urea resin; urea formaldehyde resin rus. карбамидная смола; карбамидо формальдегидная смола;… …   Chemijos terminų aiškinamasis žodynas

  • urea-formaldehyde — noun Date: 1928 a thermosetting synthetic resin made by condensing urea with formaldehyde …   New Collegiate Dictionary

  • urea-formaldehyde resin — noun a clear thermosetting resin made from urea and formaldehyde and used in electrical fittings, adhesives, and finishes • Hypernyms: ↑synthetic resin * * * noun : a thermosetting synthetic resin made by condensing urea with formaldehyde and… …   Useful english dictionary

  • urea-formaldehyde resin — /yoo ree euh fawr mal deuh huyd , feuhr , yoor ee euh /, Chem. any of a group of resins formed by the interaction of urea and formaldehyde under conditions that include heat and pH control: used chiefly in the manufacture of buttons, baking… …   Universalium

  • urea-formaldehyde resin — noun Any of several of the condensation products of the reaction between urea and formaldehyde (and their derivatives) used as a thermosetting material …   Wiktionary

  • urea-formaldehyde resin — ure′a formal′dehyde res in n. chem. any of a group of resins formed by the interaction of urea and formaldehyde, used chiefly in the manufacture of buttons and baking enamels …   From formal English to slang

  • urea formaldehyde — /juˌriə fɔˈmældəhaɪd/ (say yooh.reeuh faw malduhhuyd) noun a chemical used in the production of rigid plastics of many uses, as in particle board, adhesives, house insulation, etc …  

  • urea formaldehyde resin — Смотри карбамидоформальдегидная смола …   Энциклопедический словарь по металлургии

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