Valorization of Agricultural Residues for Cellulose Nanofibrils Production and Their Use in Nanocomposite Manufacturing

Abstract

This paper reports the isolation of cellulose nanofibrils (CNFs) from almond stems, available as agricultural residues. The CNF suspensions were prepared by the combination of chemical and mechanical treatment: the microscopic fibres were firstly isolated by the delignification-bleaching process, followed by TEMPO-mediated oxidation to facilitate the further nanofibrillation using high-pressure homogenization process at 600 bar for 10 passes as a mechanical treatment. The ensuing CNFs were characterized by several methods, such as transmission electron microscopy (TEM), degree of fibrillation, and carboxyl content. Different nanocomposites were prepared by casting-evaporation method from the mixture of CNF suspension in the commercial acrylic latex as a matrix. The effect of CNF loading on mechanical and thermal properties of the composites was then studied. The considerable enhancement of both Young’s modulus and tensile strength was observed, which clearly indicates that the nanocomposites reinforced with the nanofibrils from Prunus amygdalus have promising mechanical properties.