Date of Award

January 2015

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Materials Engineering

First Advisor

John E. Blendell

Second Advisor

Jonathan J. Wilker

Committee Member 1

Jeffrey P. Youngblood

Committee Member 2

Rodney W. Trice

Abstract

Studying how marine organisms make tough biologic materials that autonomously heal allows us to integrate this biological self-healing motif into synthetic biomimetic polymers. These types of polymers will be used to develop components with greater fatigue life and toughness, promoting greater resource sustainability by reducing plastic consumption. The amino acid 3,4-dihydroxyphenylalanine (DOPA) grants marine mussels the ability to strongly affix themselves to the rocks under water by forming strong reversible bonds with their environment. Poly[(3,4-dihydroxystyrene)-co-styrene)] (P[3,4-DHS-S]) is a synthetic polymer mimic of DOPA with chemical structure similar to polystyrene (PS) with a potential self-healing mechanism. This intrinsic self-healing mechanism works to toughen and reform bonds to inhibit or retard crack propagation without external stimuli and energy. This work investigates the critical stress intensity for propagating preexisting cracks induced by a Vickers indentation in P[3,4-DHS-S], and the effects that different cross-linking agents have on crack growth within the polymer matrix. A Life Cycle Assessment (LCA) is also performed to give component designers supplemental information needed to evaluate any differences between using P[3,4-DHS-S] as an alternative to PS in terms of environmental and economic sustainability.

Download

Share

COinS