Degree Name

Master of Science (MS)

Semester of Degree Completion

1994

Thesis Director

Jerry W. Ellis

Abstract

Molecular recognition has recently emerged as a unique technique for making synthetic polymers with selective binding cavities which can stereoselectively and regioselectively bind to a template molecule in a fashion similar to natural enzymes and antibodies. Its industrial applications in chemistry and biomedicine have been recently exploited. Typical examples include the resolution of amino acids, enantio-separation of racemates and bioactive molecules, selective binding of metal ions and in HPLC investigations. Our research is focused on applying molecular recognition studies to improve the regioselectivity of sucrose reactions.

Sucrose is an abundant industrial raw material of immense industrial importance however, its full commercial utilization is severely limited by the lack of regioselectivity in many synthetic reactions. This is due to the eight reactive hydroxyl groups on the sucrose molecule. Our strategy is to use a molecule of similar structure to sucrose, in our case, p-nitrophenyl α-D-glucopyranoside, to serve as a template. From this, a monomer, p-nitrophenyl 2,3,4,6-tetra-O-methacryloyl-α-D-glucopyranoside is synthesized and copolymerized with styrene and divinylbenzene to form a three dimensional cross-linked polymer matrix. Removal of the template molecule from the polymer matrix by hydrolysis would create cavities on the polymer whose functional groups can "recognize" and bond to the template molecule and ultimately with the glucose end of sucrose. This way we can block the hydroxyls on the glucose part of sucrose from further reactions whilst a number of reactions can be done with the fructose hydroxyls. Alternatively a reaction might possibly be performed on the sucrose in the cavity.

Not much attention has been given to the set of experimental conditions necessary for the synthesis of polymer imprints which are macroporous, spherical and have a high surface area. In order for the polymers to be selective a macroporous state is very desirable since it permits access to a large surface area and thus a larger number of cavities. This thesis deals with the task of finding the necessary conditions for the synthesis of macroporous polymers, their characterization and surface area measurement.

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