Browsing by Author "Calambas, Heidy Lorena (Directora)"
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Item Preparación y propiedades fisicomecánicas de películas almidón termoplástico/ácido poliláctico en presencia de un tensoactivo no iónico(Universidad Santiago de Cali, 2022) Ruiz Navia, Eliana Marcela; Caicedo Cano, Carolina (Directora); Calambas, Heidy Lorena (Directora)Miscibility in biopolymeric blends is a critical process that requires evaluation of the effect of surfactants or coupling agents under conditions similar to processing. Different mixtures in the molten state of plasticized starch and polylactic acid in the presence of a surfactant (Tween 20) at different concentrations were studied. This allowed knowing the rheological, thermal, and surface behavior of the mixtures. The results of the dynamic rheological analysis showed increases in viscosity in the presence of the surfactant, in which strong interactions were produced at high shear rates that reflect possible crosslinking between the polymer chains, in addition to intermolecular interactions that were evidenced in the infrared spectrum. Likewise, the storage and loss moduli showed transitions mainly from viscous to elastic typical for thermoplastics. The thermogravimetric analysis did not show significant changes between the mixtures, however, the calorimetric analysis showed changes in the crystallinity of the mixtures, and the tensoactive promotes greater freedom of movement and rearrangements in the microstructure as observed in the micrographs SEM with a decrease of the interface between polymers and less compaction of the material induced by the emulsion. The analysis of the interaction between these biopolymeric films with moisture (water) shows changes at reduced times, where the AS50PLA50-T10 blend is favored, however, when the films of the thermoplastic starch – polylactic acid (TPS-PLA) blends are immersed in water, the absorption remains constant without the presence of surfactant generates an effect.