Ran Jiang

Degree Name

Master of Science (MS)

Semester of Degree Completion

1992

Thesis Director

Jerry W. Ellis

Abstract

The world economy is critically dependent upon natural resources. Because sucrose can be inexpensively produced in large quantities and refined to a purity unequalled by almost all other natural products, it has been exploited as an industrial raw material for many years, primarily as a sweetener. A major difficulty in utilizing sucrose as an industrial feedstock is the lack of regioselectivity in synthetic reactions due to its eight hydroxyl groups of similar reactivity.

The long range goal in this work is to apply the technique of molecular recognition by template imprinting to the creation of a material that will bind to sucrose and block certain of the hydroxyl groups. Sucrose is a disaccharide composed of D-fructose and D-glucose with the glucose in a chair conformation. The strategy is to use D-glucose as a template to synthesize a monomer with covalently bonded vinyl groups. The monomer would be copolymerized with another monomer and a crosslinking agent to prepare a three-dimensional polymer, incorporating the glucose template. Removal of the glucose would leave a cavity with the same conformation as the glucose part of the sucrose molecule. Sucrose should then bind to the polymer cavity. This method could increase the regioselectivity of reactions of sucrose by blocking the glucose end of sucrose to permit reactions to occur on the fructose portion. Alternatively, a reaction could occur within the cavity. The stereochemistry of the functional groups inside the cavity would be primarily responsible for the molecular recognition characteristics of the cavity.

Methyl 2,3,4,6-tetra-O-methacryloyl-α-D-glucopyranoside, 4-nitrophenyl 2,3,4,6-tetra-O-methacryloyl-α-D-glucopyranoside, and 4-nitrophenyl 2,3,4,6-tetra-O-methacryloyl-β-D-glucopyranoside were chosen as possible monomers. These monomers have been synthesized and characterized by spectroscopy and elemental analysis.

Copolymerization of these three monomers with styrene and divinylbenzene have been carried out by using azobisisobutryonitrile (AIBN) as the initiator. A high concentration of crosslinking agent (divinylbenzene 50% in reaction mixture) was present in the polymerization mixtures and three-dimensional polymers were formed with high rigidity. The polymers have been characterized by spectroscopy and other techniques.

Download

Included in

Chemistry Commons

Share

COinS