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Physicochemical characterization of natural and acetylated thermoplastic cassava starch

MINA, JOSE and VALADEZ-GONZÁLEZ, ALEX and HERRERA-FRANCO, PEDRO and ZULUAGA, FABIO and DELVASTO, SILVIO (2011) Physicochemical characterization of natural and acetylated thermoplastic cassava starch. Dyna; Vol. 78, núm. 166 (2011); 166-173 DYNA; Vol. 78, núm. 166 (2011); 166-173 2346-2183 0012-7353 .

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URL oficial: http://revistas.unal.edu.co/index.php/dyna/article...

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Thermoplastic starch (TPS) was obtained from natural and acetylated cassava starch using a twin screw extruder and then conditioned at 25 ºC and 54 % of relative humidity. It was found that the crystallinity index, calculated as the ratio of the IR peaks at 1047 (crystalline phase) and 1022 cm¯¹ (amorphous phase), decreases due to the effect of a plasticization process. Also, as expected, SEM micrographs show that the plasticization process destroyed the starch granular structure almost completely and an amorphous mass was obtained. The TGA results indicated that the activation energy, Ea, was also reduced by the plasticization process. The acetylated TPS shows a decrease in Tg, in tensile strength and in the percentage of moisture absorption compared to natural TPS but a larger strain at the breaking point. This behavior suggests that the chemical modification reduces the secondary interactions between starch chains due to the substitution of the hydroxyl groups by acetates.

Tipo de documento:Artículo - Article
Información adicional:Derechos de autor reservados
Palabras clave:Thermoplastic starch, cassava starch, acetylated starch, biodegradable materials, starch plasticization, renewable materials.
Unidad administrativa:Revistas electrónicas UN > Dyna
Código ID:27834
Enviado por : Dirección Nacional de Bibliotecas STECNICO
Enviado el día :27 Junio 2014 19:02
Ultima modificación:18 Agosto 2014 18:08
Ultima modificación:18 Agosto 2014 18:08
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