Experimental research on natural colors / coatings of chitosan applied in cellulosic packaging

Abstract

The packaging industry is one of the most important sectors of the economy, recognized and diagnosed as strategic for society. With this, technologies have arisen aiming at sustainable development and the search for materials that minimize damages to the environment. At the same time, the need for innovation, quality assurance and practicality to be offered to the consumer, there is concern about its final destination in an economical and environmentally correct way. Included in this context are the cellulosic packaging and the substitution of coatings based on synthetic polymers by natural polymers. In the present work, coatings based on the chitosan biopolymer were developed with the addition of natural dyes: anthocyanin and urucum (Bixa Orellana L.), entitled PCA2 and PCU2, respectively. Samples of paper (277 g/m2) were coated and characterized as Scanning Electron Microscopy (SEM), thickness, weight and barrier properties: WVPR, COBB and tensile strength. Weight and tensile strength analyzes showed no statistical differences. There was a reduction of WVPR of the order of 38.6% and 24.2% for the PCA2 and PCU2 samples, respectively, when compared to uncoated samples (PU). Similar fact occurred with the COBB analysis, there was reduction of the order of 14.8% and 29.62%.