Synthesis and characterization of carboxymethyl cellulose from office waste paper: A greener approach towards waste management

•Carboxymethyl cellulose (CMC) was successfully prepared from waste paper.•CMC had maximum degree of substitution (DS) 1.07.•Rheological studies of CMC (DS, 1.07) showed non-Newtonian pseudoplastic behavior.•Characterization of CMC was done by FT-IR and NMR techniques.•Morphology of prepared CMC was studied by SEM.

In the present study, functionalization of mixed office waste (MOW) paper has been carried out to synthesize carboxymethyl cellulose, a most widely used product for various applications. MOW was pulped and deinked prior to carboxymethylation. The deinked pulp yield was 80.62 ± 2.0% with 72.30 ± 1.50% deinkability factor. The deinked pulp was converted to CMC by alkalization followed by etherification using NaOH and ClCH2COONa respectively, in an alcoholic medium. Maximum degree of substitution (DS) (1.07) of prepared CMC was achieved at 50 °C with 0.094 M and 0.108 M concentrations of NaOH and ClCH2COONa respectively for 3 h reaction time. The rheological characteristics of 1–3% aqueous solution of optimized CMC product showed the non-Newtonian pseudoplastic behavior. Fourier transform infra red (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscope (SEM) study were used to characterize the CMC product.