Papel kraft revestido com colágeno, glúten de trigo e nanofibrilas de celulose

Abstract

Paper is highly hygroscopic and porous, influencing barrier properties and limiting its use. Natural polymers such as collagen, wheat gluten and cellulose nanofibrils (NFC) have the potential to coat paper, enabling increased barrier properties. Papers do not have sufficient barrier properties to preserve goods from spoilage. Therefore, the objective of this work is to produce coated papers and evaluate the effect of two-layer coating on kraft paper with collagen suspensions, collagen with cellulose nanofibrils (C/NFC) with contents of 2 and 4%, wheat gluten and gluten. of wheat with cellulose nanofibrils (G/NFC) with contents of 2 and 4%. Coating weights of 5, 10, 15, 20 and 25 g/m2 were obtained. The weight, thickness, oil resistance, water absorption (COBB), wettability, water vapor transmission rate (TPVA) and morphology (MEV) of coated papers were evaluated, which were compared to paper reference kraft (80 g/m2). Scanning electron microscope (SEM) images of the coated papers showed a significant reduction in voids present in the uncoated reference kraft paper. Oil resistance increased for papers coated with collagen and collagen with cellulose nanofibrils (2 and 4%) compared to reference sack kraft paper, increased for papers coated with wheat gluten with weights of 20 and 25 g/m² and for paper coated with wheat gluten with cellulose nanofibrils 2% of grammage 25 g/m². Water absorption (COBB) decreased for papers coated with collagen and collagen with cellulose nanofibrils (2 and 4%), but for papers coated with wheat gluten and wheat gluten with cellulose nanofibrils (2 and 4%) the water absorption increased in relation to the reference kraft paper. The wettability increased for all coatings, as their contact angles were smaller than that of the reference paper (106.18°), staying below 90°, demonstrating that all coatings are hydrophilic. There was a reduction in TPVA and PVA in all coated papers compared to the reference kraft paper (80 g/m²). The best results of TPVA and PVA were observed for the collagen coating with a weight of 20 g/m² and for wheat gluten with cellulose nanofibrils (G/NFC) 2% of weight of 25 g/m², which caused a decrease in the gas permeation. It can be concluded that the collagen coating showed the best results in reducing water absorption and increasing oil resistance, which can then act as a coating material for papers.