It is used as aircraft de-icing and anti-icing fluid. The freezing point of water is depressed when mixed with propylene glycol. Propylene glycol is commonly used to de-ice aircraft Antifreeze Additionally, certain formulations of artificial tears use propylene glycol as an ingredient. Propylene glycol is also used as a solvent and carrier for many pharmaceutical capsule preparations. Many pharmaceutical drugs which are insoluble in water utilize propylene glycol as a solvent and carrier benzodiazepine tablets are one example. Propylene glycol is used as a solvent in many pharmaceuticals, including oral, injectable, and topical formulations.
#STOP PRODUCTION SYNONYM SKIN#
In alcohol-based hand sanitizers, it is used as a humectant to prevent the skin from drying. Vaporizers used for delivery of pharmaceuticals or personal-care products often include propylene glycol among the ingredients. Propylene glycol is also used in various edible items such as coffee-based drinks, liquid sweeteners, ice cream, whipped dairy products and soda.
Propylene glycol is used in water-based acrylic architectural paints to extend dry time which it accomplishes by preventing the surface from drying due to its slower evaporation rate compared to water.
Related to this application, propylene glycol reacts with propylene oxide to give oligomers and polymers that are used to produce polyurethanes. This partially unsaturated polymer undergoes further crosslinking to yield thermoset plastics. In this regard, propylene glycol reacts with a mixture of unsaturated maleic anhydride and isophthalic acid to give a copolymer.
Ī small-scale, nonbiological route from D-mannitol is illustrated in the following scheme: įorty-five percent of propylene glycol produced is used as a chemical feedstock for the production of unsaturated polyester resins. Three-carbon deoxysugars are also precursor to the 1,2-diol. This conversion is the basis of a potential biotechnological route to the commodity chemical 1,2-propanediol. Dihydroxyacetone phosphate, one of the two products of breakdown ( glycolysis) of fructose 1,6-bisphosphate, is a precursor to methylglyoxal. Lactic acid and lactaldehyde are common intermediates. S-Propanediol is synthesized via fermentation methods. This starting material is usually reserved for industrial use because of the noticeable odor and taste that accompanies the final product. Propylene glycol can also be obtained from glycerol, a byproduct from the production of biodiesel. Use of USP (US Pharmacopoeia) propylene glycol can reduce the risk of Abbreviated New Drug Application (ANDA) rejection. Further purification produces finished industrial grade or USP/JP/EP/BP grade propylene glycol that is typically 99.5% or greater. įinal products contain 20% propylene glycol, 1.5% of dipropylene glycol, and small amounts of other polypropylene glycols. Manufacturers use either non-catalytic high-temperature process at 200 ☌ (392 ☏) to 220 ☌ (428 ☏), or a catalytic method, which proceeds at 150 ☌ (302 ☏) to 180 ☌ (356 ☏) in the presence of ion exchange resin or a small amount of sulfuric acid or alkali. According to a 2018 source, 2.16 M tonnes are produced annually. Industrially, propylene glycol is mainly produced from propylene oxide (for food-grade use). The S-isomer is produced by biotechnological routes. Commercial processes typically use the racemate. The compound is sometimes called (alpha) α-propylene glycol to distinguish it from the isomer propane-1,3-diol, known as (beta) β-propylene glycol. Propylene glycol is approved and used as a vehicle for topical, oral, and some intravenous pharmaceutical preparations in the U.S. Propylene glycol is a compound which is GRAS (generally recognized as safe) by the US Food and Drug Administration under 21 CFR x184.1666, and is also approved by the FDA for certain uses as an indirect food additive. Propylene glycol is also present in propylene glycol alginate, which is known as E405. For cosmetics and pharmacology, the number is E490. In the European Union, it has E-number E1520 for food applications. It is produced on a large scale primarily for the production of polymers. In general, glycols are non-irritating and have very low volatility. It is miscible with a broad range of solvents, including water, acetone, and chloroform. Its chemical formula is CH 3CH(OH)CH 2OH.Ĭontaining two alcohol groups, it is classed as a diol. Propylene glycol ( IUPAC name: propane-1,2-diol) is a viscous, colorless liquid, which is nearly odorless but possesses a faintly sweet taste.
0 kommentar(er)
