Synthesis and Characterization of Hydroxyethyl Starch from Chips Wastes Under Microwave Irradiation

Abstract

This article focuses on the synthesis of hydroxyethyl potato starch (HEPS) for liquid hand soap by evaluating waste potato starch (WPS), a byproduct in potato chips production. It is a cheap, biodegradable, non-toxic and renewable natural polymer, available in great quantities on a global level. In a factory producing potato chips, WPS, which remained in the aqueous medium during peeling, slicing, and washing the potatoes, was purified at the desired temperature with H2O2 and NaOH. HEPSs with the molar substitution (MS) in the range from 0.298 to 0.670, were synthesized under microwave irradiation in isopropanol (IPA) and NaOH solution by adding ethylene oxide (EO) to WPS. The selected reaction parameters were the concentration of NaOH, the proportion of EO, and reaction time in an attempt to understand their effects on the reaction. Considering all the studied conditions, the highest viscosity was reached at 250 cP for the highest MS in the sample of HEPS-4 when 15 g EO was used in 20 mL solution of 40% NaOH at 40 °C for 40 min under microwave irradiation. The structure of synthesized HEPSs has been characterized by FT-IR, XRD, 1H(13C)-NMR spectroscopic methods, and the degree of molar substitution was calculated from 1H-NMR spectra. In addition, thermal stability and surface morphology of characterized HEPSs were studied by DTG-TG and SEM, respectively. The thickener effect of hydroxyethyl starch in liquid hand soap was investigated. In this way, it has been understood that in the production of liquid hand soaps, hydroxyethyl potato starch can be used instead of coco diethanolamide (CDEA).