Formaldehyde Volume

Iversen (1988) tested the carcinogenic potential of formaldehyde via classical skin-painting experiments. Formalin (37% formaldehyde volume for volume) was dissolved in distilled water and used at final concentrations of 1 and 10% formaldehyde. Hairless mice (hr/hr Oslo strain, in which spontaneous tumors have not been noted) were used. Two groups consisting of 16 males and 16 females were dosed with 0.2 mL of 1 or 10% formaldehyde in water on the skin of the back twice per week (Tuesdays and Fridays) for a total of 60 weeks. Animals dosed with 10% formaldehyde, but not with 1% solutions. 

FIG. 4. Line profile comparison of the methanol conversion (a), the C02/formaldehyde volume fraction... 

Mix 50 ml. of formalin, containing about 37 per cent, of formaldehyde, with 40 ml. of concentrated ammonia solution (sp. gr. 0- 88) in a 200 ml. round-bottomed flask. Insert a two-holed cork or rubber stopper carrying a capillary tube drawn out at the lower end (as for vacuum distillation) and reaching almost to the bottom of the flask, and also a short outlet tube connected through a filter flask to a water pump. Evaporate the contents of the flask as far as possible on a water bath under reduced pressure. Add a further 40 ml. of concentrated ammonia solution and repeat the evaporation. Attach a reflux condenser to the flask, add sufficient absolute ethyl alcohol (about 100 ml.) in small portions to dissolve most of the residue, heat under reflux for a few minutes and filter the hot alcoholic extract, preferably through a hot water fuimel (all flames in the vicinity must be extinguished). When cold, filter the hexamine, wash it with a little absolute alcohol, and dry in the air. The yield is 10 g. Treat the filtrate with an equal volume of dry ether and cool in ice. A fiulher 2 g. of hexamine is obtained. 

Method B. For some purposes a shghtly more active catalyst is obtained when it is prepared in more concentrated solutions. The procedure is the same as above, but the volumes of solution for 5 g. of metal are dilute acid, 25 ml. formaldehyde, 35 ml. potassium hydroxide, 32 g. in 32 ml. of water. 

Uses. Furfuryl alcohol is widely used as a monomer in manufacturing furfuryl alcohol resins, and as a reactive solvent in a variety of synthetic resins and appHcations. Resins derived from furfuryl alcohol are the most important appHcation for furfuryl alcohol in both utihty and volume. The final cross-linked products display outstanding chemical, thermal, and mechanical properties. They are also heat-stable and remarkably resistant to acids, alkaUes, and solvents. Many commercial resins of various compositions and properties have been prepared by polymerization of furfuryl alcohol and other co-reactants such as furfural, formaldehyde, glyoxal, resorcinol, phenoHc compounds and urea. In 1992, domestic furfuryl alcohol consumption was estimated at 47 million pounds (38). 

Other Uses. More than 70 thousand metric tons of acetone is used in smaU volume appHcations some of which are to make functional compounds such as antioxidants, herbicides, higher ketones, condensates with formaldehyde or diphenylamine, and vitamin intermediates. 

In 1993, worldwide consumption of phenoHc resins exceeded 3 x 10 t slightly less than half of the total volume was produced in the United States (73). The largest-volume appHcation is in plywood adhesives, an area that accounts for ca 49% of U.S. consumption (Table 11). During the early 1980s, the volume of this apphcation more than doubled as mills converted from urea—formaldehyde (UF) to phenol—formaldehyde adhesives because of the release of formaldehyde from UF products. Other wood bonding applications account for another 15% of the volume. The next largest-volume application is insulation material at 12%. 

Wood Bonding. This appHcation requires large volumes of phenoHc resins (5—25% by weight) for plywood, particle board, waferboard, and fiberboard. Initially, phenoHc resins were used mainly for exterior appHcations, whereas urea—formaldehyde (UF) was used for interiors. However, the concern over formaldehyde emission has caused the replacement of UF by phenol-formaldehyde adhesives. 

Particle board and wood chip products have evolved from efforts to make profitable use of the large volumes of sawdust generated aimually. These products are used for floor undedayment and decorative laminates. Most particle board had been produced with urea—formaldehyde adhesive for interior use resin demand per board is high due to the high surface area requiring bonding. Nevertheless, substantial quantities of phenol—formaldehyde-bonded particle board are produced for water-resistant and low formaldehyde appHcations. 

Spheres. HoUow spherical fillers have become extremely useflil for the plastics industry and others. A wide range of hoUow spherical fillers are currently available, including inorganic hoUow spheres made from glass, carbon, fly ash, alumina, and 2h conia and organic hoUow spheres made from epoxy, polystyrene, urea—formaldehyde, and phenol—formaldehyde. Although phenol—formaldehyde hoUow spheres are not the largest-volume product, they serve in some important appHcations and show potential for future use. 

To 500 g. (3.85 moles) of freshly distilled ethyl acetoacetate in a i-l. flask set in ice and well cooled, are added 152 g. (2.0 moles) of 40 per cent aqueous formaldehyde solution and 20-25 drops of diethylamine. The flask and contents are kept cold for six hours and are then allowed to stand at room temperature for forty to forty-five hours. At the end of this time two layers are present, a lower oily layer and an upper aqueous layer. The layers are separated, and the aqueous layer is extracted with 50 cc. of ether. The ether solution is added to the oily layer, and the resulting solution is dried over 30 g. of calcium chloride. The ether is then removed by distillation on a steam bath. The residue, amounting to approximately 500 g., is diluted with an equal volume of alcohol and is thoroughly cooled in an ice bath. Ammonia is then passed into the mixture until the solution is saturated. This requires from four to eight hours, and during this time the flask is kept packed in ice. The ammoniacal alcoholic solution is allowed to stand at room temperature for forty to forty-five hours. Most of the alcohol is now evaporated the residue is cooled, and the solid i,4-dihydro-3,5-dicarbethoxy-2,6-dimethylpyridine is removed from the remaining alcohol on a suction filter. The dried ester melts at 175-180 and amounts to 4ro-435 g. (84-89 per cent of the theoretical amount). 

Novolacs are often modified through alkylations based on reactions with monomers other than, and in addition to, aldehydes during their manufacture. Examples might be inclusion of styrene, divinyl benzene, dicyclopentadiene, drying oils, or various alcohols. Despite significant production of all of these variants, most novolac volume is produced using phenol and formaldehyde. 

Gaussian also includes a facility for estimating molecular volumes for SCRFsDipole calculations. An energy calculation run with the Volume keyword will produce an estimate value for Uq. For example, here is the output indicating the recommended value for Oq for formaldehyde (RHF/6-31+G ) ... 

After a de-nib, spray surfacer is applied to build up the film thickness before top-coating. The surfacer contains a high level of pigment and extender (at least 35% by volume) and frequently a saturated polyester resin with a melamine —or urea —formaldehyde crosslinker. The coating is applied at thicknesses up to 35 ftm and stoved for 20 min at 150-165°C. 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

It reacts with formaldehyde ter form (H0CH2)3CN02, trivial name NIB-glycer-ol. This is a large volume industrial process... 

Dark Decay of UDMH in Air, UDMH was observed to undergo a gradual dark decay in the 30,000-liter Teflon chamber at a rate which depended on humidity. Specifically, at 41 C and 4% RH the observed UDMH half-life was " 9 hours (initial UDMH 4.4 ppm) and at 40 C and 15% RH, the half-life was -6 hours (initial UDMH 2.5 ppm). The only observed product of the UDMH dark decay was NH3, which accounted for only -5-10% of the UDMH lost. In particular, no nitrosamine, nitramine, or hydrazone were observed. Formaldehyde dimethyIhydrazone was observed in previous studies which employed higher UDMH concentrations and reaction vessels with relatively high surface/volume ratios (, ) ... 

According to R. Brdicka and K. Vesely the carbonyl form of formaldehyde is reduced and the limiting kinetic current is given by the rate of the chemical volume reaction of dehydration. An analogous situation occurs for the equilibria among complexes, metal ions and complexing agents if the rates of complex formation and decomposition are insufficient to preserve the equilibrium. A simple example is the deposition of cadmium at a mercury electrode from its complex with nitrilotriacetic COO"... 

Test 3 Marquis Test Mix 1 volume of formaldehyde solution with 9 volumes of sulfuric acid. Add a drop of the reagent to the primaquine phosphate sample on a white tile an orange color is produced [2]. 

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