Hydroxycarboxylic Acids

Abstract

Hydroxycarboxylic acids are an important group of chemicals, with several members that are commercially manufactured in large volumes and have a wide range of applications. Two α‐hydroxycarboxylic acids, lactic and glycolic, and a derivative of γ‐hydroxycarboxylic acid γ‐butyrolactone are discussed in detail because of their relative commercial importance, both current and future. General classes of reactions that these acids undergo are also discussed, with specific examples of those reactions that are or could become commercially important. Current manufacturing processes for lactic and glycolic acids and γ‐butyrolactone are briefly outlined, with estimates of the production volume and market size for various applications. For lactic acid production and manufacture of its derivatives for biodegradable polymers, new processes are emerging, and some of the recent patents and emerging technologies are highlighted. Some of the important uses of hydroxycarboxylic acids are related to environmentally friendly products and processes such as biodegradable plastics for consumer products and nontoxic and easily degradable solvents, cleaning agents, plasticizers, etc. The emergence of new technologies for efficient and economical manufacture of these chemicals, combined with these product opportunities, could make these hydroxycarboxylic acids very large‐volume chemicals of global commercial importance.

Direct Conversion of Cellulose to Glycolic Acid with a Phosphomolybdic Acid Catalyst in a Water Medium

“…Indeed, HPAs have been widely used as catalysts or catalyst supports for biomass conversion. ,− Most of these previous studies utilized the strong acidity of HPAs for hydrolysis − or involved the use of noble metals to convert biomass through hydrogenation − and oxidation. − Herein, we demonstrate that in addition to the strong acidity that facilitates the hydrolysis and fragmentation of cellulose, certain HPAs have moderate oxygen activation abilities that allow them to oxidize carbohydrates. The best result is achieved by H 3 PMo 12 O 40 , which enables the production of glycolic acid, an important compound widely used in organic synthesis, biodegradable polymer synthesis, skin-care products, industrial rust removal, and food processing, , from commercial α-cellulose powder with a yield of 49.3%. Interestingly, H 3 PMo 12 O 40 is even capable of converting raw cellulosic materials, such as bagasse and hay, to glycolic acid with remarkable yields of ∼30%.…”

A Short Method for the Synthesis of Hydroxyoleic Acids

“…Hydroxycarboxylic acids are a subclass of carboxylic acids of broad interest, ranging from short‐ (e.g. lactic acid) to long‐chain components (Lipsa et al, 2010; Ranathunge et al, 2011), which can be obtained from natural sources or by chemical synthesis (Datta, 2004). Hydroxycarboxylic acids and their derivatives find multiple applications in different fields as dermopharmaceuticals and cosmetics (Dal Farra et al, 2002; Green et al, 2009), in the chemical modification of surfaces due to their attitude to forming self‐assembling monolayers, and in the perfumery industry.…”

Catalytic Upgrading of Fermentation‐Derived Organic Acids

“…Lactic acid has both a carboxylic acid function and a hydroxyl group, making it reactive in a variety of chemical conversions to useful products. The chemistry of lactic acid is comprehensively compiled in a text by Holten (18), and several review articles have summarized its properties and reactions (19)(20)(21)(22)(23). Lactic acid is currently receiving a great deal of attention as the feedstock monomer for biodegradable polylactic acid polymer production.…”