A renewable cellulose-rich biofiller material extracted from waste banana stem fibers for reinforcing natural rubber composites

The study contributes to the development of sustainable and eco-friendly materials and offers a new way to utilize agricultural residues such as banana stem waste. In this study, natural fibers extracted from banana stem waste were utilized as a feedstock for the isolation and enrichment of cellulosic material using a chemical treatment method. This chemical treatment was carried out using an alkali solution (5-20% NaOH (w/v)) followed by chlorination with 20% sodium hypochlorite solution. It results in a highly porous structure of the material, which was observed in the surface morphology study. Thermogravimetric analysis shows the enhancement in the thermal stability of the treated sample compared to raw biomass. The carbon black (CB) was partially replaced with cellulose-rich fibrous powder from banana natural fibers (BNFs) in rubber compounding at 30 and 50% replacement levels. The results showed that, due to the addition of fibrous biofiller powder, there was a reduction in the tensile strength of rubber composites as compared to conventional CB-loaded compounds; however, the highest tensile strength of rubber composites was observed at 30% CB replacement with the biofiller compared to other combinations of treated BNFs-CB-loaded composites. Hence, with better functional and performance properties, the biofiller from BNF can be a potential reinforcement material for rubber composites for use in applications like rubber sheets, carpet pads, shower mats, weather-stripping, and many more. The resultant rubber products filled with biofiller material can lead to higher sustainability due to their biodegradable nature.