Caracterização de filmes híbridos entre nanocelulose de origem vegetal e bacteriana

Abstract

Among the various applications, nanotechnology has been aimed at improving the performance of products and packaging, as it can confer exclusive characteristics hitherto restricted to other materials in new products, providing the population with quality of life and food safety. Thus, this thesis aimed to characterize and evaluate the performance of hybrid films composed of plant cellulose (PC) and bacterial cellulose (BC). This, protocols were used to supply sources of micro/nanofibers, vegetable (Eucalyptus Pinus) and bacterial. For the production of bacterial cellulose, pre-tests were carried out to define the best dosages and green tea after that, by the cellulose production method, hybrid films are produced in different proportions of vegetable and bacterial cellulose, being them (%): 0, 25, 50, 75 and 100. The characterization of the suspension was performed by transmission electron microscopy (TEM) and the morphological characterization of the films was applied to scanning electron microscopy (SEM). In addition, contact angle and wettability tests were carried out by the goniometer method, barrier properties were obtained by means of water vapor permeability (WVP) tests, grease resistance and mechanical characterization was carried out by tests of tensile and puncture strength. The results showed that the morphologies of the different origins of nanocellulose affected the physical, mechanical and barrier properties of the films produced. Tensile strength, Young's modulus and punching force decreased with increasing BC content in the films, while the wettability of the films increased. All film compositions showed high resistance to grease impregnation. The contact angles with water were higher for pure films produced with plant nanocellulose. On the contrary, wettability was higher for films produced with higher BC content. Compositions with lower BC contents tend to have lower water vapor permeability values among the compositions studied. The mechanical properties were considerably higher for films composed of plant nanocellulose. Likewise, puncture force results significantly decreased with higher percentages of BC. As the films are generated from biodegradable raw materials, with peculiar mechanical properties, their uses can be expanded to replace other plastic materials, such as cellulose-based packaging materials, bags, cardboard and surface coating applications.