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CF Industries Holdings, Inc. is an American manufacturer and distributor of agricultural fertilizers, including ammonia, urea, and ammonium nitrate products. The company is based in Northbrook, Illinois, a suburb of Chicago, [3] and was founded in 1946 as the Central Farmers Fertilizer Company.
Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, [1] is a nontransparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesives, plywood, particle board, medium-density fibreboard (MDF), and molded objects.
Urea-formaldehyde (UF) Phenol formaldehyde (PF) See also. Formaldehyde (disambiguation) This page was last edited on 26 December 2024, at 19:48 (UTC). Text is ...
The basic reaction of urea and formaldehyde to create a urea-formaldehyde resin, followed by the condensation [12] Urea-formaldehyde resins (UF) are a class of impregnation resins for wood modification made by reacting urea with formaldehyde. This resin can be polymerized after impregnation into the wood substrate by oven-curing.
Some people have a contact allergy to imidazolidinyl urea causing dermatitis. [3] Such people are often also allergic to diazolidinyl urea. In addition to being an allergen, it is a formaldehyde releaser, since it generates formaldehyde slowly as it degrades. Although the formaldehyde acts as a bactericidal preservative, it is a known carcinogen.
The result was Aerolite, a urea-formaldehyde adhesive which unlike conventional glues of the time, resisted water and micro-organisms. Further research showed that gap-bridging hardeners incorporating formic acid enabled Aerolite to be used as an assembly adhesive. Aerolite was the first adhesive of its type to be invented and manufactured in ...
Sensitization to formaldehyde has been decreasing since 1980 due in part to the replacement of formaldehyde by these formaldehyde releasers. [2] As of 2009, frequency of sensitization to formaldehyde is stable at 2–3% in Europe. [2] It might be as high as 9% in the USA. [2] [13]
Methylene ureas, e.g. methylene diurea, were commercialized in the 1960s and 1970s, having 25% and 60% of the nitrogen as cold-water-insoluble, and unreacted urea nitrogen in the range of 15% to 30%. In the 1960s in the U.S., the Tennessee Valley Authority National Fertilizer Development Center began developing sulfur-coated urea.