Tuesday, May 15, 2012

what is Formaldehyde


Formaldehyde is an amoebic admixture with the blueprint CH2O. It is the simplest anatomy of aldehyde, appropriately its analytical name methanal.
A gas at allowance temperature, formaldehyde is achromatic and has a appropriate pungent, acerbic odor. It is an important forerunner to abounding added actinic compounds, abnormally for polymers. In 2005, anniversary apple assembly of formaldehyde was estimated to be 23 actor tonnes (50 billion pounds). Bartering solutions of formaldehyde in water, frequently alleged formalin, were aforetime acclimated as disinfectants and for canning of biological specimens.
In appearance of its boundless use, toxicity and volatility, acknowledgment to formaldehyde is a cogent application for beastly health. On 10 June 2011, the US National Toxicology Program has declared formaldehyde as "known to be a beastly carcinogen".
In photography, formaldehyde is acclimated in low concentrations for action C-41 (color abrogating film) balance in the final ablution step, as able-bodied as in the action E-6 pre-bleach step, to anticipate the charge for it in the final wash.
Formaldehyde is acclimated abundantly in the woodworking and cabinet-making industries. Urea-formaldehyde is acclimated in the glues that band atom lath together. The atom lath is acclimated beneath copse appearance and artificial laminate. Cabinets, coffer counters, and veneered and laminated woodwork all use atom lath absolute urea-formaldehyde beneath the artificial coat and copse veneer.
Industrial applications
Formaldehyde is a accepted architecture block for the amalgam of added circuitous compounds and materials. In almost adjustment of abbreviating consumption, articles generated from formaldehyde cover urea formaldehyde resin, melamine resin, phenol formaldehyde resin, polyoxymethylene plastics, 1,4-butanediol, and methylene diphenyl diisocyanate. The bolt industry uses formaldehyde-based resins as finishers to accomplish fabrics crease-resistant. Formaldehyde-based abstracts are key to the accomplish of automobiles, and acclimated to accomplish apparatus for the transmission, electrical system, engine block, aperture panels, axles and anchor shoes. The amount of sales of formaldehyde and acquired articles was over $145 billion in 2003, about 1.2% of the Gross Domestic Product (GDP) of the United States and Canada. Including aberrant employment, over 4 actor plan in the formaldehyde industry beyond about 11,900 plants in the U.S. and Canada.
When reacted with phenol, urea, or melamine, formaldehyde produces, respectively, harder thermoset phenol formaldehyde resin, urea formaldehyde resin, and melamine resin, which are frequently acclimated in abiding adhesives such as those acclimated in plywood or carpeting. It is acclimated as the wet-strength adhesive added to germ-free cardboard articles such as (listed in accretion concentrations injected into the cardboard apparatus headstock chest) facial tissue, table napkins, and cycle towels. They are aswell foamed to accomplish insulation, or casting into moulded products. Assembly of formaldehyde resins accounts for added than bisected of formaldehyde consumption.
Formaldehyde is aswell a forerunner to polyfunctional alcohols such as pentaerythritol, which is acclimated to accomplish paints and explosives. Added formaldehyde derivatives cover methylene diphenyl diisocyanate, an important basic in polyurethane paints and foams, and hexamine, which is acclimated in phenol-formaldehyde resins as able-bodied as the atomic RDX. Formaldehyde has been begin as a contaminant in several ablution products, at levels from 54–610 ppm: it is anticipation to appear from the breakdown of preservatives in the products.
Disinfectant and biocide
An aqueous band-aid of formaldehyde can be advantageous as a antibacterial as it kills a lot of bacilli and fungi (including their spores). Formaldehyde solutions are activated topically in anesthetic to dry the skin, such as in the assay of warts. Abounding aquarists use formaldehyde as a assay for the parasites Ichthyophthirius multifiliis and Cryptocaryon irritans
Formaldehyde is acclimated to inactivate bacterial articles for adulteration vaccines (vaccines that use an abeyant bacterial adulteration to aftermath immunity). It is aswell acclimated to annihilate exceptionable bacilli and bacilli that adeptness alloy the vaccine during production. Urinary amplitude infections are aswell generally advised application a acquired of formaldehyde (methenamine), a adjustment generally called because it prevents overuse of antibiotics and the resultant development of bacterial attrition to them. In an acerbic ambiance methenamine is adapted in the kidneys to formaldehyde, which again has an antibacterial aftereffect in the urinary tract. This is not safe for continued appellation use due to the baleful aftereffect of formaldehyde. Some contemporary creams, cosmetics and claimed hygiene articles aswell accommodate derivatives of formaldehyde as the alive capacity that anticipate the advance of potentially adverse bacteria.
Tissue fixative and embalming agent
Octopodes preserved in formaldehyde solution
Formaldehyde preserves or fixes tissue or beef by a admixture of capricious (short acknowledgment time and low temperatures) and irreversible (long acknowledgment time and college temperatures) cross-linking of primary amino groups in proteins with added adjacent nitrogen atoms in protein or DNA through a -CH2- linkage. This is exploited in ChIP-on-chip transcriptomics experiments, area nucleotide-binding proteins are cross-linked to their affiliated bounden sites on the chromosome and analyzed to actuate what genes are adapted by the proteins. Formaldehyde is aswell acclimated as a denaturing abettor in RNA gel electrophoresis, preventing RNA from basic accessory structures. A band-aid of 4% formaldehyde fixes anatomy tissue specimens at about one mm per hour at allowance temperature.
Formaldehyde solutions are acclimated as a fixative for microscopy and histology, although the allotment formaldehyde acclimated may alter based on the adjustment of analysis. Additionally, the booze acclimated to balance formaldehyde may baffle with the adeptness to appropriately fix tissue or cells, and accordingly bartering formaldehyde affairs are accessible that are packaged in bottle ampules beneath an apathetic gas to anticipate the use of communicable booze for stabilization. Formaldehyde-based solutions are aswell acclimated in embalming to antisepticize and briefly bottle beastly and beastly remains. It is the adeptness of formaldehyde to fix the tissue that produces the clue compactness of beef in an embalmed body. In column mortem examinations a action accepted as the "sink test" involves agreement the lungs of an beastly in an aqueous band-aid of formaldehyde; if the lungs float it suggests the beastly was apparently breath or able to breathe at the time of death.
Although formaldehyde solutions are frequently acclimated as a biological attention medium, usually for abate specimens, it usually just prolongs the corrupt process.
Several European countries bind the use of formaldehyde, including the acceptation of formaldehyde-treated articles and embalming. Starting September 2007, the European Union banned the use of formaldehyde due to its baleful backdrop as a biocide (including embalming) beneath the Biocidal Articles Directive (98/8/EC). Countries with a able attitude of embalming corpses, such as Ireland and added colder-weather countries, accept aloft concerns. Despite letters to the contrary, no accommodation on the admittance of formaldehyde on Annex I of the Biocidal Articles Directive for product-type 22 (embalming and taxidermist fluids) had been fabricated as of September 2009.
Drug testing
Formaldehyde, forth with 18 M (concentrated) sulfuric acerbic makes Marquis reagent which can be acclimated to analyze alkaloids and added compounds.

Tuesday, May 8, 2012

the usage of Triethanolamine


Triethanolamine chemical properties:
The triethanolamine alkaline weaker than ammonia (pKa7.82), the nature of the tertiary amine and alcohol. And low temperature organic acid salt, ester produced at high temperatures. Generate two to four ligands with a variety of metal chelates. Hypochlorous acid oxidation to generate the amine oxide. Periodate oxidation decomposition into ammonia and formaldehyde. Sulfuric acid generated morpholino ethanol. Triethanolamine at low temperature can absorb acidic gases, high temperature release.
Triethanolamine  is used as plasticizers, neutralizers, lubricants, additives or corrosion inhibitors, as well as textiles, cosmetics, humidifying agents and dyes, resins such as dispersing agent. Curing agent for epoxy resin, with a reference to the amount of 12-15 parts (by mass), the curing conditions of 80 / 4h or 120 ° C / 2h. Can also use synthetic surfactants, detergents, stabilizers and fabric softener raw materials. Used in cosmetic formulations and fatty acids into soap and sulfated fatty acid into the amine salt. The wash liquid used for the removal of acid gases such as hydrogen sulfide and carbon dioxide in the exhaust gas treatment. Also be used for the vulcanization activator of natural rubber, synthetic rubber, nitrile rubber polymerization activators, can also be used as a lubricant and anti-corrosion additives.
2 triethanolamine salt of long chain fatty acids is almost neutral and can be used as the emulsifier of oils and waxes. The oleic acid soap can increase gasoline washing capacity; stearic acid soap for fragrance cosmetics. Triethanolamine can be used as casein, shellac, dyes, solvents. Can also be used in industrial gas purification agents, fiber treatment agents, anti-corrosion additives, plasticizers, moisturizers, chelating agents, rubber vulcanization accelerator agents, photographic developer additives, detergents, cement enhancers, anti-coke additive.
Used as corrosion inhibitors, triethanolamine is an important inhibitor component of the boiler water treatment, automotive engine coolant, drilling and cutting oil. Can also be used for surface active agents, textile specialties, waxes, polishes, herbicides, petroleum demulsifiers, cosmetics, cement additives, cutting oils.
Used as GC stationary liquid metal masking agent, with agents, emulsifiers, dry cleaners, solvents, softeners, and for resin synthesis.Triethanolamine is mainly used for the preparation of surfactants, detergents, stabilizers, emulsifiers, fabric softeners. Triethanolamine in the liquid detergent can be improved removal of oily dirt, especially non-polar sebum, and the same time, by increasing the alkaline can improve the performance of decontamination. In addition, liquid detergent, its compatibility is excellent.
Solution of triethanolamine and its salts as additives of cement grinding process can not only prevent aggregation and cushion the role of the process of pulverizing powder to improve the mobility and the packing density of the cement, but also can reduce the power consumption of the shredder.
In alkaline zincate galvanized and zinc complex, increase the cathodic polarization of the bath, the coating crystalline detailed, high levels of lower deposition rate, the low will cause the coating gray rough, dispersing power poor, the general content of 20 ~ 30mL / L. However, the viscosity of triethanolamine, the maximum current density of the bath decreases.