Melamine oxalate

Melamine and its derivatives are effective fire retardants for pure nylons because they provoke melt dripping and extinction of the flame without combustible drops, whereas the melamines are ineffective in the reinforced nylon-6 [143]. In the framework of a systematic mechanistic study of halogen-free fire retardant nylon-6, combustion performance and thermal decomposition behavior of non-reinforced nylon-6 with added melamine, melamine cyanurate, melamine oxalate, melamine phthalate, melamine pyrophosphate or dimelamine phosphate were studied [144],... 

Melamine can also be added to a UF-resin in the form of melamine salts like acetates, formates or oxalates [31-34]. These decompose in the aqueous resin mix at higher temperatures and enable considerable savings of melamine for the same degree of water resistance compared to traditionally prepared MUF-resins. These salts can act additionally as hardeners. 

Thompson, M.E., Lewin-Smith, R., Kalasinsky, V.F., Pizzolato, K.M., Fleetwood, M.L., McElhaney, M.R., Johnson, T.O. (2008). Characterization of melamine-containing and calcium oxalate crystals in three dogs with suspected pet food-induced nephrotoxicosis. Vet. Pathol. 45 417-26. 

Some polymers containing heterocycles can be included in resins following further condensation. This is possible, for example, for poly(furfuryl alcohol), which can condense with formaldehyde, phenol, melamine and urea. Furfuryl alcohol-formaldehyde copolymer can be synthesized in the reaction of furfuryl alcohol with formaldehyde in the presence of oxalic acid as catalyst. 

Numerous substances such as calcium, magnesium, and phosphate, administered to rats and/or mice, have been demonstrated to lead to formation of urinary solids and are listed in Table 19.1. This table includes not only a large number of natural, essential ingredients in om diet, but also a number of substances that are formed from normal intermediary metabolism, such as carbonate, oxalate, cystine, urate, and uracil, which are present in normal urine. Numerous synthetic chemicals also produce urinary solids when administered at very high doses, including agrichemicals (such as sulfosulfuron and Fosetyl-Al), industrial chemicals (such as melamine), and pharmaceuticals (such as sulfonamides, carbonic anhydrase inhibitors, and HIV protease inhibitors). 

The formation of salts with melamine (1.3,5-triazine-2,4,6-triamine) is the most extensively studied reaction of this type. In most cases, melamine acts as a monoacidic base and forms salts with mineral acids, e.g. hydrochloric acid, nitric acid or sulfuric acid, inorganic complexes, e.g. hydrogen tetrachloroaurate(III) or dihydrogen hexachloroplatinate(IV) and a large variety of organic acids, e.g. acetic acid, oxalic acid, picric acid or some sulfonic acids.30... 

Flash/transported (indirect convection) because the contact time is very short, transported driver is ideal for temperature sensitive material examples, foodstuffs coffee, maize gluten, maleic acid, oxalic acid, starch, proteins for stearates, PVC, adipic acid, aluminum oxide, CMC, dicalcium phosphate, fumaric acid, melamine. The inlet gas temperatures for flash dryers range from 175 to 750 °C and the typical exit gas temperatures range from 50 to 200 °C the exit air temperature is usually 20 °C greater than exit dry solid temperature. Gas velocity 3-30 m/s (usually 20 m/s) or 2.5 to 3 times the terminal velocity of the particles gas requirement 1-5 Nm /kg solid or 1-10 kg air/kg solid 4000-10 000 kJ/kg water evaporated. Heat transfer coefficient for gas drying h = 0.2 kW/m K and wall to gas/particles U = 0.1 kW/m K. At AT = 550 °C (the difference between inlet and exit gas temperature), the air usage/evaporation rate is 2 or 7.2 m /s/kg/s of water evap. At AT = 220 °C 4 or 14.4 m /s/kg/s of water evap. At AT about... 

Glyceraldehyde Glycolic acid Glyoxal Melamine Methylcellulose Oxalic acid dihydrate Sodium acetate anhydrous Sodium bisulfide Sodium chlorate Sodium chromate Sodium chromate tetrahydrate Sodium polymetaphosphate tanning, soft leather Glutaral... 

Melamine can also be added in the form of melamine salts, such as acetates, formiates, or oxalates (47-53), which decompose in the aqueous resin mix at higher temperatures. The melamine is then incorporated into the UF resin, forming an MUF resin and generating acids as latent hardeners. Furthermore it has been reported that using this procedure with melamine salts, the amount of melamine needed is much lower than in other MUF resins (47-52). MUF resins can also contain various other compounds that can react with formaldehyde such as urea derivatives, guanamines, or amides (54,55). 

In a typical process for the preparation of a methylated product, formalin is adjusted to pH 8 and melamine is added to give a melamine to formaldehyde ratio of 1 3.3 molar. The mixture is heated at 70°C for about 15 minutes until the melamine has completely dissolved. The solution is then either spray-dried or allowed to crystallize to give a solid composed essentially of monomeric methylolmelamines. This product is heated with about twice its weight of methanol and oxalic acid (0.5%) at 70°C until a clear solution is obtained. The solution is adjusted to pH 9 and concentrated to 80% solids under reduced pressure. The major component of this solution is the trimethyl ether of trimethy lolmelamine ... 

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