Formaldehyde compounds

Using formaldehyde, compounds of type 5-[(2-amino-5-selenazolyl)-methylene]selenazoline are obtained (Scheme 45) (48). 

Urea reacts with formaldehyde compounds such as monomethylolurea, NH2CONHCH2OH, dimethylolurea, HOCH2NHCONHCH2OH, and others, depending on the mol ratio of formaldehyde, to urea and upon the pH of the solution. Hydrogen peroxide and urea give a white crystalline powder, urea peroxide, CO(NH2 (2 -H2 02, known under the trade name of Hypersol, an oxidizing agent. 

Various formaldehyde condensates have been developed to reduce the irritancy associated with formaldehyde while maintaining activity and these are described as formaldehyde-releasing agents or masked-formaldehyde compounds. 

The oxidation of an undisclosed methanol derivative to the corresponding formaldehyde compound is a large-scale BASF process which was established in recent years, whereas the similar methanol-to-formaldehyde process, performed on a much larger scale, has been practised at BASF for more than 100 years [1,49-51, 108]. The exact nature of the substituent(s) was not disclosed by BASF for reasons of confidentiality, although many publications on that topic appeared. The nature of the substituent makes the derivative, as the results of the investigations show, more labile to temperature. 

Figure 15.3 The reaction of a glycine derivative and a formaldehyde compound with a C q molecule leads to the formation of a fulleropyrrolidine.

Sorbitol and glycerine are commonly used as monomers for oxide addition. Various alkyl phenol-formaldehyde compounds are examples of polymeric acceptor compounds having a large number of unreacted hydroxyl groups. The extent of oxide polymerization can have a significant impact on performance and solubility of the dehazer or demulsifier in fuel and oil systems. 

Various hyposulphite compounds are used for industrial purposes including stable aldehyde compounds. Of these the formaldehyde compound (Formosul) is tie most important, since it is the reducing agent almost universally employed in applying vat dyes by printing methods to textile materials. The less stable sodium hydrosulphite is used in dyeing with vat dyes. Stable zinc compounds (Rongalite) are also on the market. 

The Baker-Perkins double-screw mixer-extruders manufactured in the USA and Great Britain are employed for processing thermosetting materials, more specifically, urea-formaldehyde compounds. Basic specifications of these units are given in Table 5 26). 

Although epoxies dominate the thermoset fracture literature, work has been reported on other systems, e.g., polyester resins, phenol-formaldehyde compounds, peroxide cured polystyrene, and highly crosslinked polyurethanes. In general, these materials exhibit fracture behaviors similar to epoxies, and suggest that thermosets, as a class of materials, display characteristic crack growth properties. 

KAURIT S is a urea-formaldehyde compound its composition is roughly that of dimethylol urea. The product is supplied in the form of white, fine powder with almost 100% active substance. 

KAURIT KFN is a urea-formaldehyde compound, similar to KAWRIT S in its chemical composition. In contrast to the latter, however, it is supplied in the form of a 50% homogeneous paste. 

TEXAPRET NAV is the approx. 40% solution of a urea-formaldehyde compound with neutral reaction. The product can be fixed fast to washing in combination with N-methylol compounds. 

TEXAPRET S is the approx. 55% solution of a urea-formaldehyde compound. It has medium viscosity and a neutral reaction. 

Urea-formaldehyde compound KAURIT, TEXAPRET BASF... 

Murray, G.S., An Investigation into the Chemistry of the Reactions of Phenol-Formaldehyde Compounds with Novel Crosslinking Agents, Ph.D. Thesis. Portsmouth University, Portsmouth, 1993. 

Figure 10.1 Sculptured saucepan handles injection-moulded by Healey Mouldings Ltd, Oldbury, in phenol-formaldehyde compound...

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