Shirin Shokoohi

Considering the growing reliance on nonrenewable resources and the high costs associated with electrical energy production, developing more energy-efficient industrial processes has become essential. Carboxymethyl cellulose (CMC), one of the most widely utilized cellulose derivatives globally, is traditionally produced through a two-step chemical process involving alkalization and etherification. This method typically requires large electric mixers operating for at least four hours, leading to significant energy consumption. This study explores the steep-pressing technique as a novel, non-electrical alternative for producing CMC, using varying mesh sizes of cellulose fibers within the same two-step chemical process. Comparative analyses of CMC produced through steep-pressing and mixing techniques were conducted. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) was employed to characterize the functional structure of alpha cellulose and synthesized CMC. The ATR-FTIR spectra of CMC samples displayed distinct peaks at 1415 cm⁻¹ and 1500–1640 cm⁻¹, corresponding to –CH₂ scissoring and –COO⁻ groups, confirming the substitution of several –OH groups in cellulose with carboxymethyl groups. Light microscopy images of aqueous solution films validated the absence of water-insoluble cellulose fibers and acceptable etherification in steep-pressed samples. Degree of substitution (DS) and viscosity (measured via titration and a Brookfield viscometer) revealed optimal values of 0.92 (108.7 ± 0.8 cp) for steep-pressing and 1.08 (130.8 ± 1.4 cp) for mixing methods. Efficiency analyses showed production efficiencies of 162% for steep-pressing and 182.2% for mixing techniques. Despite comparable product quality between the methods, steep-pressing significantly reduced electrical energy consumption, offering a promising alternative for small-scale industries.

Co-author/s:

Marzieh Alidadi-Shamsabadi, Academic Staff, Chemistry & Chemical Engineering Technical Centre, Academic Centre for Education, Culture and Research (ACECR), Isfahan University of Technology.