Characterization of some water-soluble graft copolymers synthesized by the mutual irradiation of an amphoteric ionomer and hydroxyethylcellulose using Cobalt-60 gamma irradiation.

摘要

The grafting of vinyl monomers onto polysaccharides has been the subject of extensive investigation using tetravalent Cerium and Cobalt-60 gamma irradiation as initiators. The possibility of using water-soluble grafted polysaccharides as viscosity modifiers in displacement fluids for enhanced oil recovery, personal care products, paper products, and the ability of some hydrophilic saccharide graft copolymers to absorb large amounts of aqueous fluids have generated considerable interest in both academic and industrial research. These products have many different applications and hold industrial promise for the future. In this investigation, the reason for using the Cobalt-60 gamma irradiation initiating system for grafting is due to the fact that the Cobalt-60 irradiation procedure appears to introduce higher percentages of acrylamide and sulfopropylbetaine onto the hydroxyethylcellulose backbone than the Cerium(IV) technique.; The focus of this research was to synthesize and characterize a series of graft copolymers consisting of acrylamide and two sulfopropylbetaines, each separately grafted to hydroxyethylcellulose. Two different mole ratios of the monomer grafted to the hydroxyethylcellulose were each separately subjected to three different dosages of Co-60 gamma irradiation. In addition, native hydroxyethylcellulose was subjected to three different dosages of irradiation. Graft copolymer compositions were determined by elemental analysis using the elements N and S. They were compared to the compositions determined by UV-VIS spectroscopy. Furthermore, structural analysis of the synthesized compounds were performed by proton and C-13 NMR, and FTIR spectroscopy. Ethylene Oxide molar degree of substitution (EOMS) of the native and irradiated samples of hydroxyethylcellulose were determined by Union Carbide employing the modified Zeisel method using gas chromatography. This data was used to complement copolymer composition determined by elemental analysis. Solution properties of the polymers were investigated using shear-dilution viscometry employing a four bulb viscometer, a Brookfield cone-and-plate viscometer, and multi-angle laser light scattering. The trends of the solution behavior of these polymers were investigated hydroxyethylcellulose. Laser light scattering was employed to determine the molecular weight, the radius of gyration, and the second virial coefficient of the polymers.; Finally, all of these polymers, except for one particular copolymer of as a function of irradiation dosage and initial mole ratios of monomer grafted to hydroxyethylcellulose-graft-acrylamide, and three particular copolymers of HEC-g-(3-SPDMAPMA) were water-soluble. This finding may be an insight as to how these copolymers may be crosslinked so as to form a water-insoluble, superabsorbent polymer.