Homogeneous Hydrophobic Modification of Hydroxyethyl Cellulose in Ionic Liquids

Hydrophobic modification of hydroxyethyl cellulose is carried out in ionic liquids homogeneously, with bromododecane as the etherification agent. FTIR, XRD, XPS, and DSC analysis are used to characterize the obtained products. The effect of reaction temperature, time and the content of bromododecane on the viscosity of the aqueous solution of the modified product are discussed in detail. It is found that when hydroxyethyl cellulose is modified with the optimal conditions (at 80°C for 6 h), the crystalline structure changes to amorphous completely, the degree of substituent is 0.27, the glass transition point increases from 102.1 to 128.6°C. The thickening property, viscosity temperature resistance and salt tolerance before and after grafting long alkyl chain into the molecular chains are compared. It concludes that by hydrophobically modifying hydroxyethyl cellulose with long alkyl chains, all the above properties can be significantly improved, which may extremely expand the applications of hydroxyethyl cellulose.