Melamine derived catalyst

Alkylated triazines of the current have also been prepared by heating melamine or melamine derivative and an alcohol in the presence of a hydrogenation-dehydrogenation mixed catalyst such as 5% palladium on carbon (50% hydrated) with 25 mg of Cu0/Cr203/Ni0/Ba0 and is reviewed (4). 

By the propoxylation of the synthesised melamine derived Mannich base, without catalyst, a hexafunctional polyether polyol is obtained (reaction 15.40). 

Amino Resins. Amino resins (qv) include both urea- and melamine—formaldehyde condensation products. They are thermosets prepared similarly by the reaction of the amino groups in urea [57-13-6] or melamine [108-78-1] with formaldehyde to form the corresponding methylol derivatives, which are soluble in water or ethanol. To form plywood, particle board, and other wood products for adhesive or bonding purposes, a Hquid resin is mixed with some acid catalyst and sprayed on the boards or granules, then cured and cross-linked under heat and pressure. 

Ammonium polyphosphates, on the other hand, are relatively water insoluble, nonmelting solids with very high phosphorus contents (up to about 30%). There are several crystalline forms and the commercial products differ in molecular weights, particle sizes, solubilities, and so on. They are also widely used as components of intumescent paints and mastics where they function as the acid catalyst (i.e., by producing phosphoric acid upon decomposition). They are used in paints with pentaerythritol (or with a derivative of pentaerythritol) as the carbonific component and melamine as the spumific compound.22 In addition, the intumescent formulations typically contain resinous binders, pigments, and other fillers. These systems are highly efficient in flame-retarding hydroxy-lated polymers. 

Derivation (1) By heating urea and ammonia. The resulting mixture of isocyanic acid and ammonia reacts over a solid catalyst at approximately 400C to form melamine. (2) From cyanamide, dicyanamide, or cyanuric chloride. 

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). 

Two-Package Coatings with Aminoformaldehvde Cure. One component consists of a hydroxyl-terminated urethane prepolymer while the other component is an alkyl ether (usually methyl or butyl ether) of a methylolmelamine or methylolurea derivative (melamine- or urea-formaldehyde condensation products or derivatives thereof) (140, 141). Various catalysts may be employed to accelerate the heat cure (. 125 C) and to lower the curing temperature. Curing results by splitting off of the respective alcohol, as shown ... 

Chem. Descrip. Phosphoric acid deriv. in butyl alcohol Uses Catalyst to accelerate low temp, cure of partially alkylated melamine-formaldehyde resins, high -NH containing melamine-formaldehyde resins, and convenfional butylated and isobutylated melamine-formaldehyde resins... 

Pyrovatex CP (Ciba Geigy), the A-methylol derivative of dimethylphosphonopropionamide reacted with a melamine/formaldehyde condensate used with an acid catalyst such as phosphoric acid ... 

The catalyst or add source can consist of ammonium phosphate or polyphosphate salts, phosphoric add-derived amides or alkyl or halo-alkyl phosphates. Charring agents are based on molecular structures that can form cross-linked networks such as pentaerythritol, sorbitol, melamine, and phenol-formaldehyde resins. Other polymeric systems capable of intumescence are some polyamides and polyurethanes. Blowing agents help form a porous structure in the char and can fadlitate its formation. Common blowing agents are based on urea and urea-formaldehyde resins, melamines, and polyamides that can liberate moisture. 

Butanol is used to produce plasticizer-type esters like phthalates, phosphates, sebacates, oleates, and stearates. Two important ester derivatives, n-butyl acetate and n-butyl acrylate, used in the coating are produced from n-butanol. Glycol ether derivatives like ethylene glycol monobutyl ether (EB) used in the coating industry is the product of the n-butanol reaction with ethylene oxide in the presence of an acidic catalyst. Other important derivatives of n-butanol include butyl amines and butyl esters used as herbicides, butyl xanthate ore flotation aids, butylated urea, and melamine-formaldehyde resins. 

In a recent report, [46] Liao and coworkers systematically studied the effects of the addition of transition metals (Mn, Fe, Co, Ni, Cu) on the structure and performance of doped carbon catalysts derived from PANI and melamine. The results show that the doping of various transition metals significantly affects the structures and performance of the catalysts. Doping with Fe or Mn led to a catalyst with a... 

Peng H, Liu F, Liu X, Liao S, You C, Tian X, Nan H, Luo F, Song H, Fu Z, Huang P (2014) Effect of transition metals on the structure and performance of the doped carbon catalysts derived from polyaniline and melamine for ORR application. ACS Catal 4 3797-3805... 

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