Title

Investigations of Poly[(styrene-co-p-methylstyrene)- b-isobutylene-b-(styrene-co-p-methylstyrene)] and Poly[(acrylic acid)-b-styrene-b-isobutylene-b-styrene-b-(acrylic acid)]

Date of Award

2006

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

First Advisor

Kenneth A. Mauritz

Advisor Department

Polymers and High Performance Materials

Abstract

The p Me study was conducted to understand the morphological and physical property changes that occur as the ratio of p Me to styrene is increased, effectively increasing the aliphatic units. By the introduction of p Me, the interface region becomes more blended/compatible as the p Me migrates to the interface. These p Me groups are theorized in effect to create multiple `anchors' to distribute the loads experienced at the interface more effectively creating a synergistic effect on the final properties of the copolymers. The primary goals of the pentablock study were the characterization of unique membranes as related to the morphologies and physical properties of poly[(t -butyl acrylate)-b -styrene- b -isobutylene-b -styrene-b -( t -butyl acrylate)] and poly[(acrylic acid)-b -styrene- b -isobutylene-b -styrene- b -(acrylic acid)]. Specifically, the reaction to convert t -butyl acrylate to acrylic acid group as well as the anhydride ring formation and stability as it relates to morphology was explored. The overall morphologies of these pentablocks demonstrate more restrictions due to the architecture of the chain, and these three articulated phase morphologies create an opportunity for use in diffusion and charge transport in these polymers. Investigations in morphologies, physical properties, nanoindenation, permeation, diffusion, conductivity, and dielectric relaxation spectroscopy were conducted as a function of increasing acrylic acid in the pentablocks.