Novel synthesis of coordination biopolymer precursor from oxidation of methyl cellulose by alkaline potassium permanganate

Abstract

Purpose of the study: Synthesis of diketomethyl cellulose. Materials and method: Diketomethyl cellulose was quantitatively prepared by the oxidation of methyl cellulose by potassium permanganate in alkaline medium at pH`s > 12. Results: The dike to-derivative was characterized by formation of 2,4-dinitrophenyl hydrazone and dioxime derivatives when reacting with dinitrophenyl haydrazine and hydroxyl amine, respectively, as well as by the FTIR spectral bands observed at 1760-1730 cm-1 that characterize to the carbonyl group of α-diketones. Conclusion: This oxidation product can be used as a dietary fiber and a functional fiber when added to food. In addition, it found that the product has a high affinity for chelation with most of divalent and polyvalent metal ions forming stable coordination biopolymer complexes of methyl cellulose. The product is characterized by its non-toxicity, low cost and high performance. Diketomethyl cellulose can be used effectively for removal of poisonous heavy metal ions such as Sn2+, Cd2+, Hg2+ and Pb2+, Ca2+ along with other divalent and polyvalent metal ions which are contaminated in wastewater and environment. Introduction Cellulose is the major component of cell walls in plant. It is considered as a dietary fiber as well as a functional fiber when added to food [1]. Methyl cellulose (MC) is a cellulose ether derivative. It is a water-soluble due to the presence of hydroxyl moieties at C-2 and C-3 positions which prevent extensive hydrogen bonding. It is a hydrophilic macromolecule unless the temperature exceeds that of the lower critical temperature of solution (LCST) of the approximate range 40-70 οC [2]. Therefore, this natural polymer is expected to have advantageous as a dietary fiber in food industry. The kinetics and mechanisms of oxidation of polysaccharides such as alginates [3], pectates [4], methyl cellulose [5,6], carboxymethyl cellulose [7], carrageenan [8,9] and chondroitin-4-sulfate [10] by alkaline permanganate have been investigated in more details as reported elsewhere. However, the synthesis of the keto-derivatives for the oxidation of products of the studied polysaccharides was reported elsewhere [11,12], it seems that no mention on the synthesis of the methyl cellulose keto-derivatives. Moreover, it was reported that the high tendency of alginate polysaccharide to form coordination biopolymers with polyvalent metal cations was attributed to the presence of both carboxylate and hydroxyl groups within the monomers [13]. This means that the presence of such groups in particularly the carboxylate groups within the monomers is essential for formation of such coordination biopolymer complexes. Despite the absence of carboxylate groups within the skeleton of the synthesized diketo-methyl cellulose, preliminary experiments indicated *Correspondence to: Hassan RM, Chemistry Department, Faculty of Science, Assiut University, Assiut 71516 Egypt, Tel: 01116770589; E-mail: rmhassan2002@yahoo.com