SYNTHESIS AND CHARACTERIZATION OF CARBOXYMETHYLATED CORNSTARCH

Zh. A. Nurakhmetova, Э. П. Курбашев, Bagadat S. Selenova, Tina Borke, Vladimir O. Aseyev, Sarkyt E. Kudaibergenov

2019

Full text Open access: Green Metadata (CSL-JSON)
DOI 10.32014/2019.2518-1491.1
Data confidence 70 medium
How this score is calculated

It is built from checkable properties of the record itself: whether the article has a DOI, how many independent sources confirmed its data, whether the required fields are filled in, and how recent the latest confirmation is. Disagreement between sources and a missing identifier lower it. A value of 80 or above means the record was published without further checking; 60 to 79 means it is published at reduced confidence, with a manual check advisable. A record verified by an editor by hand is never pushed below 90 by a recalculation. This scores our data about the article, not the article itself.

Abstract

The aim of this study is preparation and characterization of carboxymethylated cornstarch (CMCS) for potential application as water based drilling fluids. The cornstarch was modified by sodium monochloroacetate. The structure of cornstarch and CMCS was established by H-1 NMR and FTIR spectroscopy. The degree of carboxymethylation of cornstarch determined by H-1 NMR spectroscopy was equal to 80%. The viscosity-average molecular weights (M-eta) of pristine cornstarch and CMCS calculated from Mark-Kuhn-Houwink equation [eta]=K-eta.M-a are equal to 2.15.10 (3) g.mol(-1) and 2.75.10(5 )g.mol(-1) respectively. The temperature dependent viscosity of CMCS was measured in water by Ubbelohde viscometer, while the rheological properties of CMCS in dependence of polymer concentration and ionic strength of the solution were evaluated by rheoviscometer. The thermal characteristics of samples were determined by differential scanning calorimeter (DSC) and thermogravimetric (TGA) and differential thermal analyzer (DTA). The morphological properties of cornstarch and CMCS were studied by scanning electron microscopy (SEM). The structural-mechanical, filtration and filter cake forming properties of drilling fluids and fluid loss indicators of CMCS were found.