Analysis of Lactic Acid-Lactate Ester Systems

Kinetics of Methanol–Lactic Acid Reaction - Reactions with 85% Acid

“…At intervals ampoules were removed from the bath, chilled in an ice bath, and broken open. Weighed aliquots were analyzed for total lactic acid by a method previously reported (16).…”

Volumetric Analytical Methods for Organic Compounds

“…The composition is obtained from a calibration curve. By a combination of determination of free carboxyl groups by titration and a calculation of the amount of hydrolysis of the polylactic acids (based on a curve showing hydrolysis ratios as a function of temperature and time) it is possible to determine the composition of reaction mixtures of lactic acid with methanol, both during the reaction and at equilibrium (139).…”

Esterification

“…The K, values for the 1,3-and 1,4-acids are of the same order as that for hexahydrobenzoic acid but those for the 1,2-acids are much smaller (168). Equilibria determinations for 85% lactic acid and methanol seem to show that K increases from 2.39 to 4.96 as the ratio of methanol to the acid is lowered from 7.5 to 1 to 0.90 to 1 (170). The polycondensation of alkyldicarboxylic acids with glycols follows the kinetics of Flory: Alkyl groups reduce the probability factor (73).…”