Physicochemical, spectroscopic and thermal properties of microcrystalline cellulose derived from corn cobs

Background: Low-cost and suitable microcrystalline cellulose powders for use in the pharmaceutical industry can be derived from agricultural residues. Most commercial microcrystalline cellulose powders are produced from dissolving pulp obtained from expensive hard woods using concentrated acids. α-Cellulose was extracted from an agricultural residue (corn cob) using a non-dissolving method. The spectroscopic, thermal and physicochemical properties of the derived α-cellulose and microcrystalline cellulose powders were compared with AvicelW PH 101 (Fluka, New South Wales, Australia), a commercial brand of microcrystalline cellulose (MCCA), using standard methods. Results: X-ray diffraction showed that the microcrystalline cellulose samples obtained from maize cobs had diffraction pattern characteristics of both cellulose I and cellulose II, whereas MCCA had that of cellulose I; however, all the microcrystalline cellulose samples had similar crystallinity index (CI) values. Infrared spectroscopy results showed that the microcrystalline cellulose samples had comparable CI values and molecular structure. Thermogravimetric analysis and differential scanning calorimetry data showed quite similar thermal behaviour for all cellulose samples. Comparison of physicochemical properties of the microcrystalline cellulose powders obtained from maize cob and MCCA mainly suggests that all the celluloses have similar flow and compression properties. Conclusions: For almost all of the characterizations carried out, it was observed that the microcrystalline cellulose powders obtained from corn cob had similar characteristics to the MCCA, showing that it can be a good low-cost alternative to the expensive commercial brand.