Date of Award

5-2008

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Materials Science and Engineering

Advisor

Pennington, William T

Committee Member

Hanks , Timothy W

Committee Member

Ellison , Michael S

Committee Member

Brown , Philip J

Committee Member

Lickfield , Gary C

Abstract

Polydiacetylenes (PDAs) exhibit a chromatic response to solvents, temperature, strain and other environmental perturbations. When formed in a solid-state polymerization, the backbone of the polymer is planar and continuous π-overlap is observed. However, when the PDA backbone is distorted by an outside force the extended conjugation is interrupted and an optical shift from blue to red occurs. By exploiting the PDAs properties within polymer systems, smart fibers and films have been created that enhance the original intention of the host. Under this umbrella, a strain sensitive polydiacetylene-polyurethane blend was created using 3 and 4-butoxycarbonylmethylurethane PDA and a medical grade polyurethane, Tecoflex®. Additionally, a temperature sensitive material has been developed with the renewable resource polymer, polylactic acid blended with 10,12-pentacosadiynoic acid (PCDA). Finally, PCDA has been incorporated into sodium alginate to create environmentally responsive fibers. To match the aqueous solubility of the alginate, the PCDA was forced into a micellular structure through heating and probe sonication. After crystallization and polymerization, the aqueous dispersion of PCDA was combined with the sodium alginate and wet-spun into calcium alginate 'smart' fibers. All systems were monitored for response to external stimuli (blue to red) optically and quantitatively by absorbance and Raman spectroscopy.

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