Hexamethylenetetramine solid

Aqueous hexamethylenetetramine solution adjusted to pH 2.0 by addition of H2SO4 was used as a binder for particle board. The amount of hexamethylenetetramine solids was 10% of wood weight. Heating was by press platens and by high frequency temperatures ranged from 180 to 220 C with 5 min of press time. The boards pressed at 220 °C had a density of 0.75 g/cm and exhibited an IB of... 

Bromomethyl-2,3-dimethoxy-7-methylquinoxaline (265) underwent a classical Sommelet reaction and incidental hydrolysis of the methoxy groups to give 7-methyl-2,3-dioxo-l,2,3,4-tetrahydro-6-quinoxalinecarbaldehyde (266) (hexamethylenetetramine, CHCI3, 20°C reflux, 30 min solid from evapora-... 

Delepine reaction org chem Slow ammonolysis of alkyl halides in acid to primary amines in the presence of hexamethylenetetramine. del-3,pTn re,ak-sh3n deliquescence phys chem The absorption of atmospheric water vapor by a crystalline solid until the crystal eventually dissolves into a saturated solution. del-3 kwes-3ns ... 

Shan et al. first illustrated this solid-state enhancement technique in the context of cocrystals of the compound cyclohexane-l,3cfs,5cfs-tricarboxylic acid (CTA) 28 [55]. CTA readily formed phase-pure cocrystal material with hexamethylenetetramine (HMTA) 29 upon grinding for 20 min (as judged from powder XRD data). 

Hexamethylenetetramine Explosive. A powerful solid explosive was claimed to have been prepd by oxidizing hexamine with a solution of hydrogen peroxide, treating the resulting product with nitric acid and then, reoxidizing with H202 (Ref 1). After drying, this was mixed with AN, castor oil and turpentine (Ref 2)... 

HEXAMINE. CAS 100-97-0], (CH-),N . formula weight 140,19, white crystalline solid, mp 280rC. decomposes at higher temperatures. Alsu known as hexamethylenetetramine, nicihenuiniiie. and urotiopitie. the compound is soluble in H2O and only very slightly soluble in alcohol or ether. Although used to some extent in medicine as an internal antiseptic, the primary use of hexamine is in the manufacture of synthetic resins where the compound is a substitute for formalin (aqueous solution of paraformaldehyde) and its NaOH catalyst. Hexamine also is used as an accelerator for rubber. 

The novolac foams are made by mixing the solid (powdered) oligomer (70 parts), carbon filler (30 parts), and hardener (hexamethylenetetramine) in a vibromixer and then press-molding the mixture for one hour at 150 °C, at a compression of 30-40% of the initial volume39). Casting compositions curable at room temperature are made from resol cold hardening oligomers 83). 

Dissolve 71 g of 2-methylnaphthalene in 450 g (283 ml) of carbon tetrachloride and place the solution in a 1-litre three-necked flask equipped with a mechanical stirrer and reflux condenser. Introduce 89 g of N-bromosuccinimide (Section 4.2.10, p. 422) through the third neck, close the latter with a stopper and reflux the mixture with stirring for 16 hours. Filter off the succinimide and remove the solvent under reduced pressure on a water bath. Dissolve the residual brown oil (largely 2-(bromomethyl)naphthalene) in 300 ml of chloroform, and add it to a rapidly stirred solution of 84 g of hexamethylenetetramine in 150 ml of chloroform contained in a 2-litre threenecked flask, fitted with a reflux condenser, mechanical stirrer and dropping funnel maintain the rate of addition so that the mixture refluxes vigorously. A white solid separates almost immediately. Heat the mixture to reflux for 30 minutes, cool and filter. Wash the crystalline hexaminium bromide with two 100 ml portions of light petroleum, b.p. 40-60 °C, and dry the yield of solid, m.p. 175-176 °C, is 147 g. Reflux the hexaminium salt for 2 hours with 750 ml of 50 per cent acetic acid, add 150 ml of concentrated hydrochloric acid,... 

Hexamine [hexamethylenetetramine, methenamine, andurotropine, (CH2)6N4 melting point 280°C] is a white crystalline solid that decomposes at higher temperatures. Hexamine is soluble in water but only very slightly soluble in alcohol or ether. 

Tdethylamine. — Hydrogen and nitrogen are split off, a solid product with alkaline reaction, and probably possessing the composition of hexamethylenetetramine, being formed. 

No product was obtained when solid hexamethylenetetramine was substituted at this point. 

DOT CLASSIFICATION 4.1 Label Flammable Solid SAFETY PROFILE A poison by subcutaneous route. Moderately toxic by ingestion and intraperitoneal routes. Questionable carcinogen with experimental tumorigenic data. An irritant to skin, eyes, and mucous membranes. Some persons suffer a skin rash if they come in contact with this material or the fumes evolved when it is heated. Human mutation data reported. Pure hexamethylenetetramine may be taken internally in small amounts and has been used in medicine as a urinary antiseptic. Its major industrial use is in the manufacture of phenolic resins. 

Properties White, crystalline solid. D 1.82, mp 203,5C. Soluble in acetone insoluble in water, alcohol, carbon tetrachloride, and carbon disulfide slightly soluble in methanol and ether. Derivation Reaction of hexamethylenetetramine with concentrated nitric acid. 

Natural polymers crosslinked by synthetic molecules represent many resins used for industrial applications. These are now being more closely examined by solid-state NMR spectroscopy to try to understand more fully what occurs in these systems and how it is possible to improve them. Of industrial importance are the polyphenolic tannin resins crosslinked by hexamethylenetetramine. These principally contain flavan-3-ols (Fig. 15.2.18) in the tannin [21] and have been examined by CP/MAS solid-state NMR spectroscopy. Hexamethylenetetramine was used in preference to formaldehyde as it has showed a much faster rate of reaction. The intermediates in this reaction are tribenzyl-, dibenzyl-<(>, and monobenzylamines some of which rearrange to give the dihydroxydiphenylmethane crosslinking bridges in the resin. The exact nature of the crosslinking process, however, is still in debate and the study was undertaken to try and clarify the issue. To examine this process fully, a comparison was made between pine tannin (high in flavan-3-ol) (Fig. 15.2.19) pine tannin hardened with paraformaldehyde (Fig. 15.2.20) and pine tannin hardened with hexamethylenetetramine (Fig. 15.2.21). 

The solution in the pan or dish contains about a pound and a quarter of product dissolved in a bunch of water. The task now is to obtain the hexamethylenetetramine, which is a crystalline solid, from the water. To do this, first the dish is placed on the hotplate, then heat is applied to it to bring it to a slow boil. As the water boils away, portions of about 15 ml of the ammonia solution are added to it every ten minutes or so. This is to ensure that enough ammonia is present to keep any formaldehyde which may be floating around unreacted, tied up. 

HEXAMETHYLENETETRAMINE (100-97-0) Combustible solid (flash point 482°F/ 250°C). Incompatible with acids, l-bromopentaborane(9), organic anhydrides, isocyanates, vinyl acetate, acrylates, substituted allyls, alkylene oxides, epichlorohydrin, iodine, iodoform, ketones, aldehydes, alcohols, glycols, phenols, cresols, caprolactam solution, sodium peroxide, strong oxidizers. Attacks aluminum, copper, lead, tin, zinc, and their alloys, and some plastics, rubber, and coatings. 

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