Elaboração e caracterização de filmes a base de amido, gelatina, glicerol e óleo essencial

Abstract

An alternative to the plastic residues accumulation in the environment is the blend of synthetic polymers with biopolymers with e the aim to develop more easily degradable packages. The objective of this experiment was to produce biodegradable films by extrusion using manioc starch, gelatin, PBAT (polibutilene adipate co-tereftalate), glycerol and oregano essential oil, as well as to characterize the films as their mechanical properties, barrier properties, optical and their solubility. The traction and perforation mechanical properties were determinate using the texturometer equipment and to the first was used the American Society for Testing and Materials (ASTM) D822-85 standard method. The barrier properties was determinate using the ASTM E 96-95 standard method. The color was measured with a colorimeter and answers expressed in the CIELab system and the opacity calculated by the ratio of the lightness a white and black background. The solubility was determinate by the solubilized mass ratio. Obtained data were subjected to variance analysis e to the Tukey test (p<0,05). The formulation made of starch, PBAT and glycerol (F1) presented the resistance to traction the highest average value of 3,56 MPa, followed by the formulation containing essential oil (F2) with 3,08 MPa and the formulation containing essential oil and gelatin (F3) with 2,22 MPa. On the other hand, F2 presented the highest elongation value with 74,45%. The Young module did not presented significant differences. The necessary force demanded to rupture the films under perforation did not presented significant differences, although the maximum deformation average values were higher to F1 (20,41 mm) and F2 (21,34 mm). The water vapor permeability and the solubility did not presented statistical significant differences between the formulations. The L color component measured at white background presented showed the highest value to F2 (95,78) and smaller to F3 (93,83). The F3 formulation presented the highest average value to the b component with 6,71. Although, the L component at black background presented greater values to F2 (54,84) and F3 (54,78). The average value to the b component was higher to F3 (-1,80) formulation. The a component did not presented statistical differences at both backgrounds. The opacity was higher to F3 (58,41%) formulation which differed from the others. The film made of starch, PBAT, glycerol and oregano essential oil showed the best mechanical properties analyzed as elongation under traction and deformation until perforation, as well as the lowest values to opacity and higher apparent lightness.