Type of Document Dissertation Author Muggli, Mark W. Author's Email Address email@example.com URN etd-61798-17438 Title Physical Aging and Characterization of Engineering Thermoplastics and Thermoplastic Modified Epoxies Degree PhD Department Chemistry Advisory Committee
Advisor Name Title Ward, Thomas C. Committee Chair Dorn, Harry C. Committee Member Marand, Hervé L. Committee Member McNair, Harold M. Committee Member Wilkes, Garth L. Committee Member Keywords
- dilute solution
- physical aging
- relaxation time distribution
Date of Defense 1998-05-14 Availability restricted AbstractPhysical Aging and Characterization of Engineering Thermoplastics and
Thermoplastic Modified Epoxies
Mark W. Muggli
In this work the relationship between physical properties, such as physical aging
and relaxation time distributions, and chemical structure for a variety of polymeric
systems were investigated. Although there is a vast amount of physical aging data for
polymers, most of these studies do not attempt to correlate structure with physical aging.
Therefore, a set of engineering thermoplastics was examined with the goal of relating
certain of their characteristic molecular dimensions to their mechanical and volumetric
physical aging attributes.
Another series of polymeric materials, based on a poly(ether sulfone) backbone,
and having various endgroups differing in size, was also studied to determine physical
aging rates and relaxation time distributions. Furthermore, it was concluded that the
density of the poly(ether sulfones) increased while the glass transition temperature
decreased as the endgroup became smaller.
Thermoplastic toughened epoxies were also examined to clarify the importance of
covalent bonds between toughener and epoxy on physical aging, relaxation time
distributions and fracture toughness. In these studies the covalently bonded tougheners
differed from their non-reactive counterparts in the rates of volumetric physical aging at
high temperatures for the difunctional epoxy. The solvent resistance of the reactive
thermoplastic toughened tetrafunctional epoxy was higher than the non-reactive
thermoplastic toughened system. The tetrafunctional epoxies with the reactive toughener
also had higher toughener glass transition temperatures.
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