INVESTIGADORES
MANFREDI liliana Beatriz
congresos y reuniones científicas
Título:
Starch / Polylactic acid bio-based blends: Influence of the starch modification on the film properties.
Autor/es:
MALBOS, LUCIANA B.; IGLESIAS MONTES, MAGDALENA L.; CYRAS, VIVIANA P.; MANFREDI, LILIANA B.
Lugar:
Ciudad de México
Reunión:
Simposio; VII Simposio Anual de Estudiantes relacionados a la Ciencia e Ingeniería de Materiales; 2020
Institución organizadora:
Universidad Nacional Autónoma de México-Instituto de Investigaciones en Materiales
Resumen:
In recent years, polymers obtained from natural and biodegradable resources have attracted great interest due to the decrease in the reserve of fossil fuels and the growing concern about the accumulation of waste. Therefore, biodegradable polymers have been the subject of numerous investigations, in order to reduce the environmental impact. In this work it is proposed the development of a biodegradable material from bio-based polymer blends: starch and polylactic acid (PLA). In this way, the synergy between the good properties of each polymer would allow to obtain a new advanced material. On the one hand, PLA would provide better mechanical properties while, on the other hand, starch would offer good thermal properties and lower cost. These materials have a potential application as coatings of substrates such as cardboard or paper, for the development of fully biodegradable food packaging, replacing polymers derived from petroleum. Native and acetylated starch were plasticized with 30 wt.% of glycerol, a natural plasticizer to improve processability. Polymeric films with PLA/Starch and PLA/Acetiled-Starch ratio of 70/30 were obtained by melt mixing (T profile of 140?180°C and 50 rpm) and compression molding (190ºC and 70 kg/cm2). Pure PLA and blends films were characterized by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The addition of native and acetylated starch to PLA increased the crystallinity of the films, which would indicate that starch acts as a nucleating agent. Finally, PLA-based materials showed higher thermal resistance than pure PLA due to the intrinsic characteristic of starch and the increase in crystallinity of the films.