Phenolic and amino resins

Similar NMR studies have been performed on formaldehyde/melamine 

Analysis of amino resins at stages much beyond the gel point requires the 

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Amino and Phenolic Resins. The largest use of formaldehyde is in the manufacture of urea—formaldehyde, phenol—formaldehyde, and melamine—formaldehyde resins, accounting for over one-half (51%) of the total demand (115). These resins find use as adhesives for binding wood products that comprise particle board, fiber board, and plywood. Plywood is the largest market for phenol—formaldehyde resins particle board is the largest for urea—formaldehyde resins. Under certain conditions, urea—formaldehyde resins may release formaldehyde that has been alleged to create health or environmental problems (see Amino RESINS AND PLASTICS). 

Uses. About 35-40% of the methanol made is converted to formaldehyde. That s not because the embalming business is so good. Formaldehyde is a feedstock for amino and phenolic resins, which are used as adhesives in plywood, and in the automotive and appliance industry to make parts (all the agitators in washing machines used to be made out of phenolic resins). It is used as feedstock for hexamethylene tetramine, used in electronic plastics for pentaerythritol, used for making enamel coatings and for floor polish and inks for butanediol, a chemical intermediate and for acetic acid, which is widely used itself as a feedstock and solvent and warrants its own treatrnent later on. In the textile business, formaldehyde is used to make fire retardants, mildew resistant linens, and permanent press clothing. 

The largest and oldest chemical intermediate use for methanol is formaldehyde. Over half of the methanol currently consumed in the world goes into formaldehyde production. Formaldehyde is produced by the catalytic oxidation or the oxidative dehydrogenation of methanol The major outlet for formaldehyde is amino and phenolic resins. These resins are in turn used in the manufacture of adhesives for wood products, molding compounds, binders for thermal insulation and foundry resins. Formaldehyde is also consumed in the production of acetal resins, pentaerythritol, neopentyl glycol, trimethylolpropane, methylenediphenyldiisocyanate (MDI), and textile treating resins. 

Formaldehyde is used as a chemical intermediate in the manufacture of a large variety of organic compounds, ranging from amino and phenolic resins to slow release fertilizers (Gerberich et al. 1980). Table 4-3 shows the distribution of formaldehyde use for select periods between 1963 and 1977. The demand for formaldehyde in North America was 11.6 billion pounds in 1995, a slight increase from the... 

Amino and phenolic resin adhesives for plywood, fiberglass insulation, laminates, friction products, and abrasive products are reactive oligomers that cure by self-condensation... 

Methyl glucoside n. CH20HCH(CH0H)3 CHOOCH3. A plasticizer for alkyd, amino and phenolic resins. It is also used as a polyol for urethane-foam production. 

Spray drier n. A cylindrical or conical-bot-tomed chamber through which hot air rises and into which a resin emulsion is sprayed in small droplets. The solvent evaporates from the droplets as they fall and the dried-resin powder is removed from the chamber bottom by scraping or air blasting. Spray drying has been employed for emulsion-polymerized vinyl resin, and for amino and phenolic resins. 

Thermoset materials are produced by the direct formation of network polymers from monomers, or by crosslinking linear prepolymers. Important thermosets include alkyds, amino and phenolic resins, epoxies, unsaturated polyesters and polyurethanes. Thermosetting polymers consist of two liquid components, one containing a resin and the other a hardener [1]. 

These figures include resins used in the production of moulding powders. The two main moulding powders are those based on amino and phenolic resins, the consumption of which in 1970 was 43 500000 kg and 31000000 kg respectively. 

The basic chemistry and preparation of amino, and phenolic resins is covered extensively in the literature. To make water soluble or water miscible versions of these polymers most activity has concentrated on using the lower molecular weight polymers which are etherified with the lower alcohols (methanol and ethanol). 

Epoxide/amino or phenolic resin blends Stoving Addition and condensation polymerisation Blends rich in higher ketones and alcohols Good Good Very good Very good Good ... 

The United States production of amino plastics was more than 3 billion pounds in 2001. The urea-formadehyde polymers account for slightly more than 85% of the total. The amino plastics are similar in properties to the phenolics but are clearer and colorless. They are also harder but have somewhat lower impact strength and resistance to heat and moisture. The melamine resins are better than the ureas in hardness and resistance to heat and moisture. The melamine and urea resins are rated for continuous use at temperatures of 130-150°C and 100°C, respectively. The general applications of the amino and phenolic plastics are the same but there are uses where the amino plastics are superior. The melamine resins find an important niche due to their combination of clarity and lack of color compared to the phenolics and their superior hardness and heat and moisture resistance compared to... 

The methods used to increase the water resistance of a glass microsphere foam are basically those applied to glass-reinforced plastics, filled thermoplasts, and elastomers, viz. hydrophobic adhesion compounds are added to binder and microsphere dressing 147). The compounds added are alkyl alkoxysilane derivatives, amino or epoxy alkoxysilanes for epoxy and phenolic resins, vinyl or methacryloxy alkoxysilanes for polyester resins. The dressing agents used are aminoethoxysilanes (y-aminopropyl-... 

Thermoset polyester Polyester resins cross-linked with amino or phenolic resins May contain lower molecular weight epoxy resin Very good Pack dependent May not be suitable for very acidic and aggressive foods... 

Most amino and phenolic thermosets are used in the production of composites, mainly prepared with wood (wood-plastic composites, WPC) [68]. Particleboard, or the chipboard is a kind of WPC, which is produced from wood particles, such as wood chips or saw dusts, through their glueing together with synthetic resins or other suitable binders, by pressing and extruding afterwards. In most particleboards, the resin used is formaldehyde-based. 

Epoxy resin coatings are cured by copolymerization with acrylic, polysulfide, polyurethane, polyamine, polyamide, amino, and phenolic oligomers. 

Amino and phenoplast resins (like melamine, urea, and phenolic) can also be used for elevated temperature curing. They are cross-linked through the hydroxyl group of the epoxy and produce products with good chemical resistance. 

Alkyd resins saturated and unsaturated polyester resins used to produce polyurethanes and for laminating and casting. Thermosetting alkyd moulding material has various moulding advantages over aminos and phenolics. See diallyl phthalate. 

Amino resins are thermosetting polymers made by combining an aldehyde with a compound containing an amino (—NH2) group. Urea—formaldehyde (U/F) accounts for over 80% of amino resins melamine—formaldehyde accounts for most of the rest. Other aldehydes and other amino compounds are used to a very minor extent. The first commercially important amino resin appeared about 1930, or some 20 years after the introduction of phenol—formaldehyde resins and plastics (see Phenolic resins). 

Ammonia is used in the fibers and plastic industry as the source of nitrogen for the production of caprolactam, the monomer for nylon 6. Oxidation of propylene with ammonia gives acrylonitrile (qv), used for the manufacture of acryHc fibers, resins, and elastomers. Hexamethylenetetramine (HMTA), produced from ammonia and formaldehyde, is used in the manufacture of phenoHc thermosetting resins (see Phenolic resins). Toluene 2,4-cHisocyanate (TDI), employed in the production of polyurethane foam, indirectly consumes ammonia because nitric acid is a raw material in the TDI manufacturing process (see Amines Isocyanates). Urea, which is produced from ammonia, is used in the manufacture of urea—formaldehyde synthetic resins (see Amino resins). Melamine is produced by polymerization of dicyanodiamine and high pressure, high temperature pyrolysis of urea, both in the presence of ammonia (see Cyanamides). 

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