Affiliation:
1. Bukhara State University
2. Bukhara Engineering Technology Institute
Abstract
Currently, native starch as a binder and sizing component is used extremely rarely due to its inherent disadvantages. It has been replaced everywhere with modified starches of various kinds. Studies have shown that polyelectrolyte flocculants can be created on the basis of starch if ionizable groups are introduced into the macromolecules of amylose and amylopectin. At the same time, it was found that the treatment of starch with oxidizing agents (of various natures and activities) can significantly improve the functional properties of native starch when gluing, used for surface sizing, and as a binder for corrugated cardboard. In this work, we also obtained oxidized starch in order to create an adhesive binder on its basis, and only local raw materials were used. It is shown that this method makes it possible to regulate the number of functional groups (oxidizing effect, or OE) in oxidized starch and its paste viscosity within a wide range. This is achieved by changing the molar ratio of the catalyst and oxidizer. During the oxidation process, it is possible to vary the concentration ratios of the oxidizer, catalyst, and conditions. Using FeSO4 as a catalyzer, the oxidized starch pastes show a less pronounced pseudoplasticity and are characterized by reduced viscosity. The analysis showed that during the oxidation of corn starch with hydrogen peroxide, changes in the supramolecular structure of starch are insignificant: a certain repeated decrease in the level of crystallinity takes place, which leads to a decrease in the gelatinization temperature and also the viscosity of starch pastes.
Publisher
Trans Tech Publications, Ltd.
Reference28 articles.
1. E.V. Novozhilov, D. G. Chukhchin, E. V. Smirnov, E. A. Varakin, I. V. Tyshkunova. Localization and Component Status of Starch Binder in Test Liner. IVUZ. «Lesnoy jurnal». 4 (2013) 111-118.
2. Q.Wei, H.Zheng, M.Zhu et al. Starch-based surface-sizing agents in paper industry:an overview. J. Paper and Biomaterials, 6(4) (2021) 54-61
3. Morikawa, K., & Nishinari, K.. Effect of concentration dependence of retrogradation behaviour of dispersions for native and chemically modified potato starch. Food Hydrocolloids 14 (2000) 395–401.
4. The effect of polydispersity on the conversion kinetics of starch oxidation and depolymerisation;Hoogstad;Chemical Engineering Science: X
5. Mikhaylova O.S. The effect of biomodified starch on the strength and deformation properties of cardboard. Phylosophy doctoral thesis. Russia, Kazan. 2018.