Mechanical and morphological properties of cellulose biocomposites

Abstract

Natural biocomposites offer promising alternatives to petroleum-based composites thanks to their biocompatibility, sustainability, and low environmental impact. However, they must also demonstrate competitive mechanical properties and adaptability to manufacturing processes. To this end, we developed cellulosic biocomposites using plasticized cellulose acetate (PCA) reinforced with cellulosic fibers at loadings from 30 to 50 wt%. Mechanical properties were determined with tensile, bending, and impact tests and interfacial bonding was analyzed using scanning electron microscopy (SEM). Results showed that the adhesion of 50 wt% cellulose fibers increased the Young's modulus of the biocomposites by 300 % and the tensile strength by 12 %. Flexural properties also improved: the flexural modulus increased from 1.52 GPa to 5 GPa for PCA at maximum fiber loading, and from 43.3 MPa to 54 MPa for flexural strength. However, the elongation at break decreased with increasing cellulose content, from 13.5 % to 0.8 %, along with a 74 % decrease in impact strength. SEM results revealed good fiber dispersion, interfacial adhesion, porosity, and fiber pullout. These results underscore the potential for cellulose biocomposites as eco-friendly alternatives for high-value utilizations, including electronic and dielectric applications.