Acrylic acid

Acrylic acid (IUPAC: propenoic acid) is an organic compound with the formula CH2=CHCOOH. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a characteristic acrid or tart smell. It is miscible with water, alcohols, ethers, and chloroform. More than a million tons are produced annually. Acrylic acid (IUPAC: propenoic acid) is an organic compound with the formula CH2=CHCOOH. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group connected directly to a carboxylic acid terminus. This colorless liquid has a characteristic acrid or tart smell. It is miscible with water, alcohols, ethers, and chloroform. More than a million tons are produced annually. Acrylic acid is produced by oxidation of propylene, which is a byproduct of ethylene and gasoline production: Because acrylic acid and its esters have long been valued commercially, many other methods have been developed, but most have been abandoned for economic or environmental reasons. An early method was the hydrocarboxylation of acetylene ('Reppe chemistry'): This method requires nickel carbonyl and high pressures of carbon monoxide. Acrylic acid was once manufactured by the hydrolysis of acrylonitrile, a material derived from propene by ammoxidation, but this route was abandoned because ir cogenerates ammonium side products, which must be disposed of. Other now abandoned precursors to acrylic acid include ethenone and ethylene cyanohydrin. Propane is a significantly cheaper raw material than propylene, so one alternative route being explored is the one-step selective oxidation of propane. Carboxylating ethylene to acrylic acid under supercritical carbon dioxide condition is thermodynamically possible when an efficient catalyst is developed. Dow Chemical Company and its partner OPX Biotechnologies are investigating using fermented sugar to produce 3-hydroxypropionic acid (3HP), an acrylic-acid precursor. The goal is to reduce greenhouse-gas emissions. Acrylic acid undergoes the typical reactions of a carboxylic acid. When reacted with an alcohol, it forms the corresponding ester. The esters and salts of acrylic acid are collectively known as acrylates (or propenoates). The most common alkyl esters of acrylic acid are methyl, butyl, ethyl, and 2-ethylhexyl acrylate.