Characterization of carboxymethyl cellulose-based nanocomposite films reinforced with oxidized nanocellulose isolated using ammonium persulfate method

Cellulose nanocrystals (CNCs) were isolated from cotton linter (CL) and microcrystalline cellulose (MCC) using an ammonium persulfate (APS) method for a simultaneous isolation and oxidation of CNCs. The CNCs were in rod-like shape with a diameter of 10.3 nm and 11.4 nm, a length of 120-150 nm and 103-337 nm, a crystallinity index of 93.5% and 79.1% for the CNCCL and CNCMCC, respectively. The suspensions of oxidized CNCs were transparent and stable with the zeta potential values of −50.6 mV and −46.9 mV. The CNCs were uniformly distributed within the carboxymethyl cellulose (CMC) polymer matrix. The tensile strength (TS) increased by 102% and 73%, and elastic modulus (E) increased by 228% and 166% with the incorporation of at 10 wt% of CNCCL and CNCMCC, respectively. Conclusively, the CNCCL showed a more uniform particle size distribution, higher crystallinity, transparency, thermal stability, and superior mechanical strength compared with the CNCMCC.