Aplicação de taninos no recobrimento de papel kraftliner para produção de embalagens

Abstract

The demand for more sustainable packaging has been growing along with technological advancement and consumer goods sector. The use and application of plant extracts in papers can make up the production process of the packaging and add many advantages to the product, with bioactive compounds (such as tannins). The tannins are extracted from a renewable source and this thesis contributes with information about the biorefinery of the components/products of the forest. Tannins are polyphenolic compounds, used industrially for various purposes, due to their reactive character, and can be used in the production of adhesives, cosmetics and packaging coatings. In this sense the objective of this work was to develop packaging with high properties of barriers to oil, water, through the incorporation of tannins in other polymers for the development of new formulations, in addition to giving light barrier and antioxidant activity to new packaging. Tannins of acácia Negra (Acacia mearnsii) and barbatimão (stryphnodendron adstringens) were used to prepare the formulations, as well as wax of carnauba, latex, biolátex and cellulose nanofibrils. The formulations were characterized in terms of viscosity, solids content and pH. The application was performed on kraftliner paper, with the bar type laboratory coating machine. Subsequently, the barrier papers were subjected to oil kit analysis, oil kit in the crease, contact angle, wettability, Cobb 120, TPVA, surface hardness of the coating or barrier film and mechanical properties. For the evaluation of antioxidant activity, the extracting solvent was optimized and the analysis was performed with 3 different methodologies (ABTS*+, β-carotene/linoleic acid and Phosphomolybdenum Complex). The colorimetry of the papers produced was also evaluated. The results showed that the addition of tannins can favor the barrier potential, improving the characteristic of the paper surface, reducing the interaction with oils/fats and water vapours, as well as adding antioxidant characteristics, increasing the protection of the packaged product. In addition, the results proved that it is possible to reduce the amount of petroleum-based materials, such as polyacrylate varnish (PV), with the increase of renewable source material, and bring data to support additional theoretical studies.