Date of Award

Spring 5-2016

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

Committee Chair

Robson F. Storey

Committee Chair Department

Polymers and High Performance Materials

Committee Member 2

Derek L. Patton

Committee Member 2 Department

Polymers and High Performance Materials

Committee Member 3

Jeffrey S. Wiggins

Committee Member 3 Department

Polymers and High Performance Materials

Committee Member 4

James W. Rawlins

Committee Member 4 Department

Polymers and High Performance Materials

Committee Member 5

Joshua U. Otaigbe

Committee Member 5 Department

Polymers and High Performance Materials

Abstract

In the first project, an azide functional resin and tetra propargyl aromatic diamines were fabricated for use as a composite matrix. These systems take already established epoxy/amine matrices and functionalize them with click moieties. This allows lower temperatures to be used in the production of a thermoset part. These new systems yield many better mechanical properties than their epoxy/amine derivatives, but their Tgs are low in comparison.

The second project investigates the characterization of a linear system based off of the above azide functional resin and a difunctional alkyne. Through selectively choosing catalyst the linear system can show regioselectivity to either a 1,4-disubstituted triazole, or a 1,5-disubstituted triazole. Without the addition of catalyst the system produces both triazoles in almost an equal ratio. The differently catalyzed systems were cured and then analyzed by 1H and 13C NMR to better understand the structure of the material.

The third project builds off of the utility of the aforementioned azide/alkyne system and introduces an on-demand aspect to the curing of the thermoset. With the inclusion of copper(II) within the azide/alkyne system, UV light is able to catalyze said reaction and cure the material. It has been shown that the copper(II) loading levels can be extremely small, which helps in reducing the copper’s effect on mechanical properties.

The fourth project takes a look at polysulfide based sealants. These sealants are normally cured via an oxidative reaction. This project took thiol-terminated polysulfides and fabricated alkene-terminated polysulfides for use as a thiol-ene cured material. By changing the mechanism for cure, the polysulfide can be cured via UV light with the use of a photoinitiator within the thiol/alkene polysulfide matrix.

The final chapter will focus on a characterization technique, MALDI-TOF, for which was used to help characterize the above materials as well as many others. By using MALDI-TOF, the researcher is able to elicit the molecular weight of the repeat unit and end group which allows the determination of the polymer’s structure. This technique can also determine the Mn and Mw, as well as the PDI for each given polymer.

ORCID ID

0000-0002-7080-3699

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