Off-campus UMass Amherst users: To download campus access dissertations, please use the following link to log into our proxy server with your UMass Amherst user name and password.

Non-UMass Amherst users: Please talk to your librarian about requesting this dissertation through interlibrary loan.

Dissertations that have an embargo placed on them will not be available to anyone until the embargo expires.

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Polymer Science and Engineering

Year Degree Awarded

2015

Month Degree Awarded

September

First Advisor

Alan J. Lesser

Subject Categories

Materials Science and Engineering | Polymer and Organic Materials

Abstract

The focus of this dissertation is to develop a fundamental understanding of process-structure-property relationship in two different classes of polymers: semi-crystalline Ultra High Molecular Weight Polytetrafluoroethylene (UHMWPTFE) and amorphous glassy double network (DN) epoxies. Conventional melt processing techniques such as extrusion and injection molding cannot be applied to UHMWPTFE due to its very high melt viscosity (1010-1011 poise). Therefore, UHMWPTFE is industrially processed by a modified metallurgy technology-sintering. However, the fundamental mechanism for UHMWPTFE sintering is unknown. Further, this process is highly time consuming, cost inefficient and hinders the recyclability of the material. The first part of this dissertation aims at developing experimental techniques for studying the sintering process in-situ and thereby elucidates the molecular mechanism associated with UHMWPTFE sintering. Further, the effect of different fluoropolymer additives and process conditions on the sintering behavior will be studied. The second part of this dissertation aims at developing asymmetric double network epoxies where the two networks are distinct both in terms of chemical stiffness and crosslink density and correlating this complex network architecture with thermal and non-linear mechanical properties.

Share

COinS