Alginic acid gels: the effect of alginate chemical composition and molecular weight
1994
Draget, K.I. | Braek, G.S. | Smidsrod, O.
The effect of chemical composition and sequence and molecular weight of different alginate samples on the final properties of alginic acid gels have been studied. It is shown that alginates with a high content of gluronic acid blocks give gels of a considerably higher strength compared to alginates rich in mannuronate. A high fraction of homopolymeric blocks seems to favour the formation of junction zones. Compared to Ca-alginate gels, a more extended molecular weight dependent regime is observed. Kinetic measurements show an initially rapid (approximately 30 min) sol-gel transition with an apparent equilibrium in the dynamic storage moduli gradually obtained within 24-48 h, depending on the chemical composition of the alginate sample used. Mechanical spectroscopy reveals gels with a high degree of solid-like nature, with an increasing frequency dependence with decreasing molecular weight.
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