Hydroxymethyl melamine

The use of phenolic polymers in photocrosslinkable systems usually involves multicomponent systems which incorporate polyfunctional low molecular weight crosslinkers. For example, Feely et al. [9] have used hydroxymethyl melamine in combination with a photoactive diazonaphthoquinone which produces an indene carboxylic acid upon irradiation to crosslink a novolac resin. Similarly, Iwayanagi et al. [10] have used photoactive bisazides in combination with poly(p-hydroxy-sty-rene) to afford a negative-tone resist material which does not swell upon development in aqueous base. 

HEXAKIS(HYDROXYMETHYL)MELAMINE HEXAKIS-(HYDROXYMETHYL)- ,3,5-TRIAZINE-2,4,6-TRIAMINE HEXAMETHYLOLMELAMIN (CZECH) HEXAMETH-YLOLMELAMINE RESLOOM M 75 (1,3,5-TRIAZINE-2,4,6-TRIYLTRINITRILO)HEXAKIS METHANOL (s-TRLAZINE-2,4,6-TRIYLTRINITRlLO)HEXAMETHANOL 2,4,6-TRIS(BIS(HYDROXYMETHYL)AMINO)-s-TRlAZ-... 

HEXA(HYDROXYMETHYL)MELAMINE see HDYOOO HEXAISOBUTYLDraN see HDYIOO HEXAKIS([l-ACETATO)-Il- -OXOTETRABERYLUUM see BFT500... 

Tris(hydroxymethyl)ethane trinitrate M/ / / /-Tris(hydroxymethyl)melamine Tris(hydroxymethyl)methylamine Tris(methoxyethoxy)vinylsilane Tris(4-methoxyphenyl)chloroethene... 

Coley HM, Brooks N, Phillips DH, et al. The role of N-(hydroxymethyl) melamines as antitumor agents mechanism of action studies. Biochem Pharmacol 1995 9 1203-1212. 

Hexa (hydroxymethyl) melamine Hexakis (hydroxymethyl) melamine Hexakis (hydroxymethyl) 1,3,5-triazine-2,4,6-triamine. See... 

Synonyms Hexa (hydroxymethyl) melamine Hexakis (hydroxymethyl) melamine Hexakis (hydroxymethyl) 1,3,5-triazine-2,4,6-triamine Hexamethylolmelamine 1,3,5-Triazine-2,4,6-triyltrinitrilo) hexakis methanol l4,6-Tris (bis (hydroxymethyl) amino)-s-triazine Empirical CsHieNeOe Properties M.w. 306.33... 

Hexahydro-1,3,5-tris (hydroxyethyl) triazine Hexahydro-1,3,5-tris-(2-hydroxyethyl)-s-triazine. See Hydroxyethyl-s-triazine Hexahydroxycyclohexane. See Inositol Hexahydroxylene Hexahydro-m-xylene. See 1,3-Dimethylcyclohexane Hexahydro-o-xylene. See 1,2-Dimethylcyclohexane Hexahydro-p-xylene. See 1,4-Dimethylcyclohexane Hexa (hydroxymethyl) melamine. See Hexamethylol melamine resin Hexakis (dihydrogen phosphate) myo-inositol. See Inositol-hexaphosphoric acid Hexakis (dihydrogen phosphate) myo-inositol sodium salt. See Sodium phytate Hexakis (hydroxymethyl) melamine Hexakis (hydroxymethyl) 1,3,5-triazine-2,4,6-triamine. See Hexamethylol melamine resin Hexakis (methoxymethyl) melamine Hexakis (methoxymethyl)-s-triazine-2,4,6-triamine. See Hexamethoxymethylmelamine Hexakose. See 2,4-Hexadienol 5-Hexalactone... 

IR spectroscopy is used frequently for the analysis of MF-type resin materials. Despite its broad use and availability, the information is quite limited for the analysis of distinct chemical species because of broad bands and overlap with water signals (see Vibrational Spectroscopy). Information on cocondensation between phenolic resins and melamine (72,115), the structural analysis of hydroxymethylated melamines (116,117), as well as the chemistry of hardening (118) can be followed. 

Polymers. AH nitro alcohols are sources of formaldehyde for cross-linking in polymers of urea, melamine, phenols, resorcinol, etc (see Amino RESINS AND PLASTICS). Nitrodiols and 2-hydroxymethyl-2-nitro-l,3-propanediol can be used as polyols to form polyester or polyurethane products (see Polyesters Urethane polymers). 2-Methyl-2-nitro-l-propanol is used in tires to promote the adhesion of mbber to tire cord (qv). Nitro alcohols are used as hardening agents in photographic processes, and 2-hydroxymethyl-2-nitro-l,3-propanediol is a cross-linking agent for starch adhesives, polyamides, urea resins, or wool, and in tanning operations (17—25). Wrinkle-resistant fabric with reduced free formaldehyde content is obtained by treatment with... 

N,]S7-bis(methoxymethyl)uron was first isolated and described in 1936 (41), but was commercialized only in 1960. It is manufactured (42) by the reaction of 4 mol of formaldehyde with 1 mol of urea at 60°C under highly alkaline conditions to form tetramethylolurea [2787-01-1]. After concentration under reduced pressure to remove water, excess methanol is charged and the reaction continued under acidic conditions at ambient temperatures to close the ring and methylate the hydroxymethyl groups. After filtration to remove the precipitated salts, the methanolic solution is concentrated to recover excess methanol. The product (75—85% pure) is then mixed with a methylated melamine—formaldehyde resin to reduce fabric strength losses in the presence of chlorine, and diluted with water to 50—75% soHds. Uron resins do not find significant use today due to the greater amounts of formaldehyde released from fabric treated with these resins. 

Reaction of melamine with neutralised formaldehyde at about 80-100°C leads to the production of mixture of water-soluble methylolmelamines. These hydroxymethyl derivatives can possess up to six methylol groups per molecule and include trimethylolmelamine and hexamethylolmelamine (Figure 24.8) The methylol content of the mixture will depend on the melamine formaldehyde ratio and on the reaction conditions. 

The tetrakis(hydroxymethyl)phosphonium chloride so formed is the major ingredient with urea-formaldehyde or melamine-formaldehyde resins for the permanent flame-proofing of cotton cloth. 

Condensation reactions of hydroxymethyl groups on phenolic resoles and amines on melamine take place between pH 5 and 6 (Fig. 7.33). Only selfcondensations of hydroxymethyl substituents occur under strongly acidic or basic conditions. 

Hydroxymethyl-4,6-dimethylphenol, 406 Hydroxymethylphenol. See also Hydroxymethylated phenol reaction with melamine, 411 reaction with urea, 410 Hydroxymethyl substituents, condensation reactions of, 403... 

Crosslinked polymer particles with a rather complex structure, which have also been designated by the name microgels and recommended as components of metal effect paints, consist of carboxyl-terminated oligoesters of 12-hydroxy stearic acid which were reacted with glycidyl methacrylate, subsequently copolymerized with MMA and hydroxymethyl methacrylate and then crosslinked by hydroxy melamine [346]. 

Melamine dissolves in aqueous formaldehyde solution on warming, with the formation of W-hydroxymethyl compounds.The latter are crystalline substances that dissolve in hot water but are only slightly soluble in cold water. If a sample of the reaction mixture is cooled immediately after the melamine has been completely taken into solution,the poorly soluble W-hydroxymethyl compounds precipitate. 

The chemical name of this reagent is l,3-bis(hydroxymethyl)-4,5-dihydroxy-imidazolidinone-2 but it is usually called DMDHEU or the glyoxal reactant because it is prepared from glyoxal, urea, and formaldehyde. Other methylolamide agents that have been used for producing wrinkle resistance in cotton include the aforementioned urea formaldehyde, dimethylolurea, dimethylolethyleneurea, and formaldehyde adducts of melamines (triazines), acetylenediurea, propyleneurea, uron, triazones, and alkyl carbamates. Reactions between methylolamides and cellulose occur in the presence of acid (or Lewis acid) catalysts and are very fast at elevated temperatures—sufficiently so that they are adaptable to the requirements of rapid, commercial processing of cotton fabrics. 

The second type of reaction concerns the use of hydroxymethyl or, more frequently, alkoxymethyl derivatives of melamine, that is, a multifunctional amine, in aminomcthylation (or transaminomethylation) reactions. Crosslinked epoxy resins are also obtained by reaction with epoxides (Fig. 188). - -... 

Because these fire-retardant salts are water-soluble and subject to leaching, several new methods have been developed which provide a water-resistant or permanent treatment for cotton fabrics and cellu-losic materials. Perkin developed a process involving successive treatment with sodium stannate and ammonium sulfate, which precipitates stannic oxide in the cellulose libers. Antimony oxide in combination with vinyl chloride or other chlorinated polymers has also been found effective. A more recent approach to this problem involves application of fire-retardant resin-forming or cross-linking compounds. " These include materials and methods based on the copolymerization of tetrakis(hydroxymethyl)phosphonium chloride and methylol — melamine, the reaction of bromoform and triallyl phosphate to form a cross-linked polymer, and the cross-linking reaction of tris(l-aziridinyl)phosphine oxide with cellulose, or its copolymerization with tetrakis(hydroxymethyl)phosphonium chloride and other materials. ... 

Since the early days of MF condensation chemistry [11], the way of synthesis has been and is still actively researched by industrial and academic groups [12]. In a typical synthesis, a conventional MF paper impregnation resin is obtained in a polycondensation reaction of melamine with formaldehyde under basic catalysis and heat. In an initial methylolation or hydroxymethylation step, mainly three different species are generated monomethylolmelamine (mnun), dimethylolmelamine (dmm) and trimethylolmelamine (tmm). 

After hydrolysis, the silanol groups are able to condense with the reactive methylol groups in hydroxymethylated di- and trimelamine as well as with unbridged methylolated melamine species (Scheme 4) to yield the rigid and infusible three-dimensional networks between resin and silane after final curing. Of course, reactions between silanol groups and hydroxyl groups of the cellulose in the paper would seem to be possible, but this has never been proven without doubt. 

Formaldehyde release from pressed wood products is due to latent formaldehyde. During the pressing process, hot steam from moist wood particles transfers heat, formaldehyde, and other volatiles from the surface of the mat to the core of the board where un reacted urea-formaldehyde resin components accumulate. The resulting formaldehyde concentration in the core is approximately twice that of the surface. Release of formaldehyde is diffusion-controlled and gradually decreases over time (Meyer and Hermanns 1985). Formaldehyde can also be produced by hydrolytic cleavage of unreacted hydroxymethyl groups in the formaldehyde resins. Melamine formaldehyde resins generally are more stable, and the amounts of formaldehyde emitted from them are much lower (WHO 1989). 

Melamine is soluble only in water and has low solubility in dimethylsulfoxide (DMSO) and in other aprotic dipolar solvents (9% at 120 °C), in glycerol or ethylene glycol (10% at 140 °C). In the majority of other usual solvents it is insoluble. Kucharski and Lubczak discovered a new class of reactive solvents for melamine [36] poly (hydroxymethyl) derivatives of cyclohexanone, acetone, nitromethane which are able to dissolve 50-60% melamine. Melamine can be totally propoxylated or ethoxylated at lower temperatures (70-90 °C), in aprotic dipolar solvents (for example DMSO, dimethylformamide, N-methyl pyrrolidone and so on), in the presence of quaternary ammonium hydroxides as catalysts [for example tetrabutyl ammonium hydroxide (TBAH)], at a low reaction rate (reaction 15.35), for a very long reaction time (40-50 hours) [31, 37]. The resulting hexafunctional polyols give very thermostable rigid PU (up 200 °C). 

An A-acetylcysteine-melamine adduct (105) has been described as shown in Scheme 25. The mechanism probably involves a methyleneiminium ion (104). A-Hydroxymethyl compounds are produced by the metabolism of materials which contain A-methyl groups by preparations of murine liver. Hexamethylmelamine (HMM) is hydroxylated by this route, which involves cytochrome P450. As electrophiles, these A-hydroxymethyl compounds may be excreted as glutathione conjugates, hence (105) and other A-acetylcysteine and glutathione derivatives were prepared as part of a study of possible biochemical mechanisms <85JCS(Pi)75>. 

The melamine-formaldehyde system is somewhat more complicated because of the basicity of the melamine. Okano and Ogata found the hydroxymethylation to be second order, but the rate increased with increasing pH in the range of pH 3.0-10.6. 

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