Preparation And Characterization Of Dodecenyl Succinic Anhydride Derivatives Of Water Soluble Hydroxyethyl Cellulose

Hydroxyethyl cellulose has been modified using dodecenyl succinic anhydride(DDSA)in aqueous solution. Structure and property of the DHEC have been characterized. The amount of hydrophobe incorporation(HI) has been determined by a simple titration method and it is higher when DDSA/HEC in the reaction composition is higher. Reaction efficiency(RE) is higher when increased alcohol was used in the reaction mixture. ~1H-NMR and FT-IR confirm that derivatisation had occurred. Shear viscosity of DHEC with intermolecular hydrophobic associative was found to be higher than the unmodified HEC and more sensitive to shear rate. Surface tension from Du Noüy ring method of DHEC aqueous solution decreased rapidly when HI is high and reached the lowest surface tension at lower concentration. Absorbance of solutions of HEC and its derivatives in the presence of Sudan IV dye as a function of HI of DHEC and it is higher when HI is high.Rheological behavior—shear flow viscosity of quasi-binary solution(polymer+water) of DDSA modified HEC compared with HEC are studied. Different hydrophobic associative inter and intra molecular interaction of HEC derivatives in aqueous solution is analyzed as a function of the HI and concentrations of HEC derivatives. Three interaction models with various HI at different concentrations are reasonably drawn from the results. Effect of salt,such as 0.2M NaCl, on the shear viscosities of solutions of HEC and its derivatives are also investigated. Though addition of salt may strengthen the association of hydrophobic side chain, the effect is in quite different result which depended on the HI value and concentration of polymer.It’s an effective method to enhance the thickening property of HEC and its hydrophobic derivatives by increasing its molecular weight or by grafting hydrophobic side chains. Consid ering the economic and technical factors grafting saturated alkyl chain will be more preferred.