Author: Zahran, Mohamed Magdy Kandi,/ Title: Study of the Oxidative Degradation of Some Polysaccharides =

الموضوع

The present thesis aims at finding out the most appropriate conditions to oxidize the common polysaccharide maize starch using the powerful sodium perborate/aminoiminomethanesulfinic acid (SPB/AIMSA) redox system, keeping in mind the quality of the oxidized starch, the cost of the oxidizing process and its environmental impact. Structural changes in the starch molecules brought about by oxidation were appraised in terms of the carbonyl and carboxyl groups as well as the apparent viscosity. It was found that starch undergoes oxidative degradation using the said redox system. This was demonstrated by a significant enhancement of the carbonyl and carboxyl groups along with a significant decrease in the apparent viscosity as compared with the unoxidized starch. Application of the oxidized starch, prepared under the optimum oxidation conditions, to cotton fabric was also carried out to evaluate the suitability of such modified starch as sizing agents. Results of tensile strength (TS) and elongation-at-break (EAB) measurements of the fabric samples as well as the Thesis Abstract xviii easiness of size removal from these samples compared with those sized with the unoxidized starch signify that the oxidized starches are more satisfactory sizing agents. Key words: Maize starch, oxidation, sodium perborate, aminoiminomethanesulfinic acid, sizeability Microbial polysaccharides.