Mechanophore Strategies for the Development of Polymers with Mechanically Gated Responsive Behavior

Author: Barber, Ross William

Year: 2023

Degree: Dissertation (Ph.D.)

Advisor: Robb, Maxwell J.

Committee Members: Stoltz, Brian M.; Agapie, Theodor; Nelson, Hosea M.; Robb, Maxwell J.

Option: Chemistry

DOI: 10.7907/wgnw-zq30

Abstract

The development of mechanically sensitive molecules has recently enabled mechanical force to induce specific changes in polymeric materials. This document details efforts in the development of such mechanophores in which mechanical activation is used to gate the desired functional responses.

Chapter 1 is an introduction to polymer mechanochemistry and delineates the state of the field as it relates to color changing mechanophores used for damage detection. Special emphasis is placed on a system developed by our lab in which mechanical force gates the photoresponsive behavior of a diarylethene molecular switch.

Chapter 2 details the design of a new mechanically gated photoswitch whose synthesis and activity are improved from the previous iteration. The modular design enables a late-stage synthetic intermediate to be differentiated into a small library of masked photoswitches that produce unique colors following mechanical activation and ultraviolet irradiation. Notably, these mechanophores show activity in solution phase experiments as well as in bulk polymeric materials.

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