Valorization of jute biomass: performance of fiber-cement composites extruded with hybrid reinforcement (fibers and nanofibrils)

Abstract

In this study, the characteristics of jute fibers and cellulose nanofibrils (CNFs) and their impacts on mechanical strength were compared, particularly from the standpoint of their application as reinforcement in extruded fiber–cement composites. Raw jute fibers were subjected to an alkaline treatment before being fibrillated into CNFs. The fiber–cement composites were produced with jute fibers (0.5% and 2%) and CNFs (0.5% and 2%) via extrusion process. Both percentages of reinforcement were based on the cement mass. In addition, hybrid composites with a mixture of fibers and CNFs were produced. Hydroxypropyl methylcellulose and carboxylic polyether were used as additives to improve the mixture’s rheology. The composites were subjected to natural weathering for 5 months before being analyzed for their physical and mechanical properties. CNFs and jute fibers subjected to NaOH treatment presented a higher initial degradation temperature (Tonset). The apparent porosity decreased for all compositions studied, reaching a 75% reduction for the sample reinforced with 2% CNFs. Fiber–cement with a hybrid reinforcement of 1.5% CNFs + 0.5% fibers exhibited the strongest mechanical performance. All compositions showed a decrease in the modulus of elasticity after natural weathering. In contrast, the modulus of rupture and the limit of proportionality showed an average gain of 1 MPa for fiber–cement composites produced with hybrid reinforcements. The better mechanical performance of the hybrid formulations may be owing to the synergistic work of the fibers and CNFs, suggesting the potential of cellulose CNFs for use as reinforcement in cement-based composites.