Ethyl Lactate
In the α-hydroxy acid with a dimolecular structure, the methyl-OH and hydroxyl-COOH interact through condensation reactions, releasing two molecules of water to form esters, resulting in a hexamolecular heterocyclic compound.
The α-methylhexanoic acid (lactic acid bacterium) dimer structure forms lactones upon heating. When lactones and water are co-boiled, they hydrolyze back into the original compounds.
Our α-hydroxy acid.
Lactones are relatively stable chemical substances, but when heated with water, acids, or bases, they hydrolyze into α-hydroxy acids.
2-ethyl glycolide, C4H8O4, content 116, melting point 84°C
(Propiolactone, C6H8O4, melting point 124°C, boiling point 330°C, gasoline pump vacuum packaging at 220°C)
Glycolide is a white, blocky crystalline substance that is soluble in butyl acetate and water, serving as a single intermediate for biodegradable materials. Lactide is soluble in alcohol and organic solvents such as fats, slightly soluble in water, and poorly soluble in carbon tetrachloride.
There are mainly two methods for the production of ethyl lactate. One method involves the esterification reaction of ethyl glycol molecules, which, upon dehydration, forms a lower content of polyethylene glycol. Under 250 degrees Celsius, the polyethylene glycol is cracked and catalyzed to produce ethyl lactate. The price of ethyl lactate is several times that of ethylene glycol.
Another method involves using metal salts of halogenated formic acid, such as potassium, to remove metal halides and form esters.
During the traditional synthesis of glycolide, distillation is required, followed by multiple purification steps to achieve a concentrated grade. Glycolide can copolymerize with lactide to form poly(lactic-co-glycolic acid) (PLGA), a macromolecular drug carrier. It can create nanoparticles that slow the release of norethindrone. As the proportion of GA in the polymer increases, the drug release rate of norethindrone accelerates. When the ratio of the two monomers is 50:50, dissolution becomes easier. The degradation products of PLGA are lactic acid bacteria and glycolic acid, which are also by-products of the human metabolic pathway and do not cause side effects.
