INSTITUTO DE TECNOLOGIA EN POLIMEROS Y NANOTECNOLOGIA
Unidad Ejecutora - UE
Organocatalytic acetylation of starch: effect of reaction conditions on DS and characterisation of esterified granules
M.V. TUPA; J.A. AVILA RAMÍREZ; A. VAZQUEZ; M.L. FORESTI
ELSEVIER SCI LTD
Lugar: Amsterdam; Año: 2015 vol. 170 p. 295 - 302
Starch acetates with varying degree of substitution (DS) were prepared by a novel solvent-free organocatalyticmethodology. The acetylation protocol involved a non-toxic biobased a-hydroxycarboxylic acidas catalyst, and proceeded with high efficiency in absence of solvents. The effect of reaction conditionsincluding reaction temperature (90?140 C), catalyst load (0?2.3 g/g starch), acetic anhydride/starchweight ratio (6.5?13.5 g/g), and starch moisture content (0.6?14.8%) on the DS of the esters was evaluated.The analysis performed showed that the increase of temperature and catalyst concentrationresulted in higher DS values, and evidenced a beneficial contribution of native starch moisture contenton the substitution level achieved. Variation of reaction conditions allowed starch esters to be obtainedwith DS in the 0.03?2.93 range. Starch esters were characterised in terms of morphology, chemical structure,thermal properties, and distribution in polar/non polar liquid systems.