Lactic acid chemistry

Polyester chemistry is the same as studied by Carothers long ago, but polyester synthesis is still a very active field. New polymers have been very recently or will be soon commercially introduced PTT for fiber applications poly(ethylene naph-thalate) (PEN) for packaging and fiber applications and poly(lactic acid) (PLA), a biopolymer synthesized from renewable resources (corn syrup) introduced by Dow-Cargill for large-scale applications in textile industry and solid-state molding resins. Polyesters with unusual hyperbranched architecture also recently appeared and are claimed to find applications as crosstinkers, surfactants, or processing additives. 

Polylactides, 18 Poly lactones, 18, 43 Poly(L-lactic acid) (PLLA), 22, 41, 42 preparation of, 99-100 Polymer age, 1 Polymer architecture, 6-9 Polymer chains, nonmesogenic units in, 52 Polymer Chemistry (Stevens), 5 Polymeric chiral catalysts, 473-474 Polymeric materials, history of, 1-2 Polymeric MDI (PMDI), 201, 210, 238 Polymerizations. See also Copolymerization Depolymerization Polyesterification Polymers Prepolymerization Repolymerization Ring-opening polymerization Solid-state polymerization Solution polymerization Solvent-free polymerization Step-grown polymerization processes Vapor-phase deposition polymerization acid chloride, 155-157 ADMET, 4, 10, 431-461 anionic, 149, 174, 177-178 batch, 167 bulk, 166, 331 chain-growth, 4 continuous, 167, 548 coupling, 467 Friedel-Crafts, 332-334 Hoechst, 548 hydrolytic, 150-153 influence of water content on, 151-152, 154... 

Barry, J. J., Ph.D Thesis, Evaluation and Characterization of the Degradation and Silver Release From a Poly (d,l- Lactic Acid) - Silver Matrix, Department of Chemistry, University of Lowell, 1988, Bl-1,92. 

Suzuki, M. and Lund, C.W. (1980) Improved gas-liquid chromatography for simultaneous determination of volatile fatty acids and lactic acid in silage. Journal of Agricultural and Food Chemistry 28,... 

Adolph Wurtz, 1817—1884. Professor of chemistry at the ficole de Medecine in Pans. Discoverer of methyl and ethyl amines and the synthesis of hydrocarbons from alkyl iodides and sodium. He studied the oxidation products of the glycols and the homologs of lactic acid The proof of the elementary nature of gallium was demonstrated in his laboratory by Lecoq de Boisbaudran. 

Irvine s first publication (1899) dealt with the rotatory powers of the optically active methoxy- and ethoxy-propionic acids prepared from lactic acid. In those early days the Purdie reaction afforded so rich a field for investigation that Irvine and his collaborators continued work on various types of hydroxy bodies in addition to the sugars. There appeared papers on the isopropylidene derivatives and methyl ethers of glycerol and mannitol, and on the chemistry of benzoin and benzoin-like materials. The constitution of the glucoside salicin was studied and its pentamethyl ether was synthesized. 

What is interesting, however, is some of the chemistry that is not present. For example, the petrochemical industry does not have a basic feedstock in the five-carbon area and thus we see few products derived from or based on five-carbon chemistry. Optical active compounds are also missing from the petrochemical-derived product list. For example, lactic acid is now made exclusively from glucose, with the reason being that the fermentation route provides stereochemical purity that is difficult to achieve from petrochemical building blocks. 

First, Lavoisier made the chemistry of salts central to his new system of chemistry, but he did not include only those salts formed with mineral acids. He lists a large number of what we would call organic acids and describes their combinations with salifiable bases, that is, salt formation. The names of many of the acids that he lists are familiar today, including acetic acid, benzoic acid, lactic acid, and oxalic acid, which form acetates, benzoates, and so on. He did not erect a border between these compounds and mineral acids and salts they were part of a unified chemistry. 

C2 chemistry on ethanol and acetic acid, C3 chemistry on glycerol and lactic acid,... 

FIG. 9 XPS analysis of PLA-PEG microparticle surfaces showing the contribution to surface chemistry of the lactic acid, ethylene glycol, and vinyl alcohol groups. (From Ref. 37.)... 

The synthesis of a-hydroxy acids from carbonyl compounds by way of the cyanohydrin was an early discovery in organic chemistry. In 1867 Simpson and Gautier, working in Wurtz laboratory, described the cyanohydrin from acetaldehyde and hydrocyanic acid, and its conversion to racemic lactic acid by strong hydrochloric acid. 

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