Eszterek

Eszterek, the Hungarian term for esters, are a large class of organic compounds derived from carboxylic acids and alcohols by a condensation reaction that releases water. The defining feature is the ester linkage, a carbonyl group connected to an oxygen atom (R-CO-O-R′).

Esters are typically prepared by esterification (Fischer esterification) of a carboxylic acid with an alcohol in the presence of an acid catalyst. They can also be formed from acid chlorides with alcohols or by transesterification between esters.

Esters tend to have distinctive, often pleasant odors and are widely used in flavors and fragrances. They are polar enough to dissolve in organic solvents and vary in volatility. Chemically, they hydrolyze to carboxylic acids and alcohols under acidic or basic conditions.

Natural esters occur in fats and oils, where glycerol forms esters with fatty acids (triglycerides). Industrially, esters serve as solvents (ethyl acetate), plasticizers, and monomers for polyesters such as polyethylene terephthalate (PET). Fatty acid methyl esters are central to biodiesel.

Safety and environmental notes: esters generally have low toxicity but can be irritants; most are flammable. Hydrolysis or incomplete combustion can release acids or alcohols. Production and use require handling guidelines to minimize emissions and exposure.