CINÉTICA DE HINCHAMIENTO DE HIDROGELES SENSIBLES AL pH BASADOS EN ALMIDÓN Y ÁCIDO ITACÓNICO

Content Provider	Semantic Scholar
Author	Pernia, Kelly Urdaneta, José León, Orietta Oliva, H. J. Tellez Soto, Diana
Copyright Year	2014
Abstract	Se sintetizaron hidrogeles mediante copolimerizacion por injerto via radicales libres de acido itaconico (IA) sobre almidon de maiz (Alm- g -IA). Se empleo el sistema de iniciacion de oxido-reduccion (redox) permanganato de potasio (KMnO 4 )-bisulfito de sodio (NaHSO 3 ). Se investigo el efecto del grado de neutralizacion del acido y de las concentraciones del monomero y del iniciador y se comparo en cada caso con el almidon oxidado (Alm-ox). Se determinaron las cineticas de hinchamiento en agua desmineralizada, solucion salina y en soluciones amortiguadoras (pH=4-10,11). En general, los copolimeros presentaron menores porcentajes de hinchamiento que el Alm-ox, que incrementaron al aumentar la concentracion de monomero y el grado de neutralizacion y al disminuir la concentracion de iniciador. Los hidrogeles obtenidos con el mayor porcentaje de neutralizacion (Alm- g -IA 80% ) y con la menor concentracion de iniciador (Alm- g -IA 1 / 2 [I] ) presentaron los mayores porcentajes de hinchamiento en agua, de 1824 y 1562 %, respectivamente. Los hidrogeles resultaron sensibles a los cambios del pH debido a los grupos acido carboxilico injertados sobre el almidon. Hydrogels were synthesized by free radical graft copolymerization of itaconic acid (IA) onto corn starch (Alm- g -IA). The redox initiation system potassium permanganate (KMnO 4 )-sodium bisulfite (NaHSO 3 ) was used. The effect of varying the acid neutralization grade and the concentrations of monomer and initiator was studied and in each case was compared with the oxidized starch (Alm-ox). Swelling kinetics were obtained in deionized water, saline solution and buffer solutions (pH= 4-10,11). In general, copolymers had lower swelling percentage than Alm-ox, which increased with the increment of the monomer concentration and the acid neutralization and with the decrease of the initiator concentration. Hydrogels obtained with the highest neutralization percentage (Alm- g -IA 80% ) and with the lowest initiator concentration (Alm- g -IA 1/2[I] ) presented the highest swelling percentage in water, of 1824 and 1562 %, respectively. Hydrogels were sensitive to pH changes due to the presence of carboxylic acid groups grafted onto starch.
Starting Page	9
Ending Page	10
Page Count	2
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Alternate Webpage(s)	http://www.rlmm.org/ojs/index.php/rlmm/article/download/582/364
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article