Several alternatives have been considered to minimize the environmental impact caused by conventional polymers. This study aims to evaluate the chemical, mechanical and morphological properties of flexible thermoplastic films of cassava and corn starch, using glycerol and lignin as plasticizers and reinforcement. The films were produced through casting. It was observed that the presence of lignin effectively increased the maximum stress and the elastic modulus by about of 840% and 4200%, respectively, when comparing to the film containing only glycerol. In addition, lignin improved thermal properties, modified some structural properties and made the surface of the material rougher.

Biodegradable films are widely exploited among scientists nowadays. Their positive environmental impact, besides their potential to promote better food conservation and an increase in shelf life motivate research in this field. Availability, low cost and biodegradability of starch increase the interest of using this material to produce biodegradable films. However, starch films tend to be brittle and they need addition of a plasticizer to enable their usage. In this work, starch films were synthesized with different carboxylic acids as plasticizers, aiming to observe the effect of the acids' chain size in the final films properties. Oxalic, succinic and adipic acids were used. The materials were produced by casting and characterized by DSC, TG, XRD, FTIR and SEM. It was observed that the acids chain size influenced on the thermal and structural properties of the films.

Weather conditions and the Brazilian fertile soil contribute to abundant natural resources in a wide variety of fiber types. These fibers have attracted interest in Materials Science area for such characteristics as: low cost, high elasticity modulus and renewability. In this context, the objective of this work was physical, chemical and morphological characterization of purple banana fibers (Musa velutina). The following characterizations were employed: TG, DSC, FTIR, XRD, SEM, density, mechanical properties and chemical composition. The results showed that the purple banana fibers had good thermal, mechanical, morphological and structural properties. Treatment with sodium hydroxide was efficient in removing amorphous regions present on the fiber as evidenced by the chemical composition, increasing the crystallinity index. Therefore, the purple banana fiber is promising as reinforcement in polymer matrices.