Cellulose nanostructured films from pretreated açaí mesocarp fibers: physical, barrier, and tensile performance

Background: During de-pulping of açai (Euterpe oleracea) for juice production in the Amazonia, large amounts fibrous waste are daily discarded, a promising substrate high-value cellulose nanofibrils. Therefore, this study sought to evaluate modifications surface fibers submitted chemical pretreatment steps and compare quality nanostructured films produced with different cycles mechanical nanofibrillation. Results: A 2-hour (at 5% NaOH) followed by two NaOH/H2O2 bleaching resulted increased length reduced diameter compared raw while preserving fiber integrity I structure. The increase fibers’ grinding from 3 (minimum gel point) 21 (maximum suspension thickness) nanofibril higher crystallinity properties, uniform thickness, compacted morphology, smoother surface. Nanofibril formed after numbers passages exhibited similar strength, but distinct barrier properties. Conclusion: Açaí can be recommended packaging applications that demand easily dissolving, such as instantaneous food. Oppositely, açaí subjected grinder provide suitable water-resistant packaging, ideal secondary coatings papers paperboards.