Date of Award

Fall 12-1-2015

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

Committee Chair

Derek L. Patton

Committee Chair Department

Polymers and High Performance Materials

Committee Member 2

Jeffrey S. Wiggins

Committee Member 2 Department

Polymers and High Performance Materials

Committee Member 3

James W. Rawlins

Committee Member 3 Department

Polymers and High Performance Materials

Committee Member 4

Robson F. Storey

Committee Member 4 Department

Polymers and High Performance Materials

Committee Member 5

Joseph R. Lott

Committee Member 5 Department

Polymers and High Performance Materials

Abstract

Polybenzoxazines are potential high performance thermoset replacements for traditional phenolic resins that can undergo an autocatalytic, thermally initiated ring - opening polymerization, and possess superior processing advantages including excellent shelf-life stability, zero volatile loss and limited volumetric shrinkage. The simplistic monomer synthesis and availability of a wide variety of inexpensive starting materials allows enormous molecular design flexibility for accessing a wide range of tailorable material properties for targeted applications. Despite the fact, once fully cured, benzoxazines are difficult to handle due to their inherent brittleness, leaving a very little scope for any modifications. The motivation of this dissertation is directed towards addressing the common limitations of polybenzoxazines and to enable tailor made material properties for expanding the scope of future applications.

In this work, a unique approach has been demonstrated incorporating a dually polymerizable bifunctional benzoxazine based monomer; designed to form a sequentially addressable intermediate B-staged network, followed by the formation of a final hybrid network via thermal curing of benzoxazines. This strategy offers a systematic route to study the formation of glassy polymeric materials in discrete, orthogonal steps, and a handle to access a broad range of material properties within the same system. The dissertation study is focused on manipulating the monomer design, to study different cure chemistries, in conjunction with benzoxazines. These cure chemistries included - rapid UV curable thiol-ene click chemistry, thermally curable ring-opening metathesis polymerization of norbornene, and free radical photo-polymerization of meth(acrylate) functionalities. A strong fundamental understanding of structure-property relationships with respect to network structure, kinetics, processing control and material properties of the hybrid networks was established.

ORCID ID

0000-0003-1051-0963

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