Cellulose nanocrystal (CNC) from okra plant (Abelmoschus esculentus L.) stalks as a reinforcement in bionanocomposite fabrication: Extraction, processing, and characterization study

• CNCs have extracted from a beneficial source okra stick by successive chemical treatment. • The CNCs have possessed promising spherical shapes with nearly 100 nm average sizes. • They have substantial active sites like –OH, -COOH, -NH, -C-O C proved by FTIR-ATR. • The extracted CNC have shown outstanding crystallinity index value (86.09±0.001 %). • They showed exceptional thermal stability & negative surface charge (about −44 mV). Currently, CNC is attractive to the researchers to fabricate multifunctional bionanocomposite because of their outstanding physicochemical, thermomechanical, morphological properties, and eco-friendly nature. Whereas in most cases CNC is extracted from the bast/bark of primary plants, which have other beneficial applications in several sectors. Hence, it is crucial to find out alternative sources of CNCs to diminish the extra pressure on the primary plants. While the useless agrowaste biomass of okra stalks would be a new and beneficial alternative to produce CNCs as a reinforcement. Here, a series of chemical reactions were directed to produce CNCs. The samples were characterized by FTIR-ATR,TGA/DTA,FESEM,EDX,XRD,UV–vis-NIR, and DLS analysis. The obtained results suggested that the newly produced CNCs possessed substantial active functional groups(–OH,C O-C,–NH), high thermal stability, greater crystallinity(86.09±0.001 %), and notable microstructure indicating a well-organized porous surface with encouraging spherical shapes. The CNCs are free from impurities and coloring materials; additionally, they exhibit a highly negative surface charge and smaller particle sizes. It can be stated that the produced CNCs should have a good agreement with the sustainable environment and be beneficially applied as a reinforcing agent to fabricate bionanocomposites. Also acts as a sustainable alternative to the fossil-based hazardous ones for various uses.