Free Volume Studies of Various Polymeric Systems Using Positron Annihilation and PVT-EOS ...

198 Pages·2016·7.62 MB·English

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Dissertations
Fall 12-2011
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Mukul Kaushik
University of Southern Mississippi
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Kaushik, Mukul, "Free Volume Studies of Various Polymeric Systems Using Positron Annihilation and PVT-
EOS Analyses" (2011). Dissertations. 681.
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The University of Southern Mississippi

FREE VOLUME STUDIES OF VARIOUS POLYMERIC SYSTEMS USING
POSITRON ANNIHILATION AND PVT-EOS ANALYSES

by

Mukul Kaushik

A Dissertation
Submitted to the Graduate School
of The University of Southern Mississippi
in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy

December 2011
ABSTRACT
FREE VOLUME STUDIES OF VARIOUS POLYMERIC SYSTEMS USING
POSITRON ANNIHILATION AND PVT-EOS ANALYSES
by Mukul Kaushik
December 2011
The glass transition phenomenon and free volume behavior below and above the
glass transition temperature of various polymeric systems have been investigated. Several
novel polymeric systems were considered for this study. Two generations of
hyperbranched polyols, H40 and H20, were selected due to large number of hydroxyl
groups on the periphery and within the bulk. The effect of hydrogen bonds and molecular
weight was related with the glass transition and free volume behavior for the whole range
of experimental temperature. The free volume behavior was experimentally studied using
PVT and PALS to determine occupied volume, fractional free volume and number
density of holes. Molecular dynamic simulation was performed to compare atmospheric
pressure V-T data and visualize hydrogen bond structures.
Linear as well as crosslinked isomeric polymers were selected for the study of
isomerism on glass transition and free volume. Isomers were selected based on para and
meta substitution on phenylene ring in the polymer repeat unit. In this way the polymer
chemical composition was kept the same and only architecture was varied. Two linear
polymers based on isomeric repeat unit, polyethylene terephthalate (para) and
polyethylene isophthalate (meta), and five sets of epoxy networks prepared using
isomeric diamine crosslinkers, 3,3’-DDS and 4,4’-DDS were used. The crosslinked
networks followed the same trend of glass transitions and free volume properties as in
linear polymers. The glass transition temperatures of para isomer based linear polymers
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and epoxy-amine networks were higher. It was observed for linear polymers as well as
for all networks that para isomer generates structure with higher amount of free volume
in the glassy state; however, in the rubbery state they are the same. Free volume studies
were further extended for solvent uptake in epoxy-amine networks to correlate hole free
volume and van der Waals volume of solvent. The higher frozen in free volume in all
para isomers leads to higher solvent uptake as compared to meta isomers.
Pressure-volume-temperature (PVT) data were used to calculate occupied volume
and fractional free volume using Simha-Somcynsky (S-S) Equation of State (EOS).
PALS was utilized to evaluate average hole free volume for a wide range of temperature.
Both PALS and PVT were utilized to evaluate occupied volume and hole number density.
The PVT fractional free volume was also correlated with positron annihilation lifetime
spectroscopy (PALS) hole free volume, v , and ortho-positronium formation intensity, I ,
3 3
to calculate the correlation coefficient, C.
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COPYRIGHT BY
MUKUL KAUSHIK
2011
The University of Southern Mississippi

FREE VOLUME STUDIES OF VARIOUS POLYMERIC SYSTEMS USING
POSITRON ANNIHILATION AND PVT-EOS ANALYSES

by

Mukul Kaushik

A Dissertation
Submitted to the Graduate School
of The University of Southern Mississippi
in Partial Fulfillment of the Requirements
for the Degree of Doctor of Philosophy

Approved:

Sergei Nazarenko .
Director

Jeffrey Wiggins .

Derek Patton .

James Rawlins .

Robson Storey .

Susan A. Siltanen .
Dean of the Graduate School

December 2011
DEDICATION
This dissertation is dedicated to my parents, Saroj and Om Prakash Sharma,
without whom none of this would have been possible

iii
ACKNOWLEDGMENTS
I would like to acknowledge my graduate research advisor, Dr. Sergei Nazarenko,
for being a great friend and mentor. I greatly appreciate the guidance and support of my
committee members: Dr. Jeffrey Wiggins, Dr. James Rawlins, Dr. Robson Storey and
Dr. Derek Patton. I thank you all for your persistence in the pursuit of scientific
excellence and your guidance in becoming a better scientist.
I would like to acknowledge the Nazarenko Research Group for their help with
research, and more importantly, for making this a fun place to work. The Wiggins
Research Group is appreciated for their help in the Cytec-Boeing Project and The
Rawlins Research Group for the GE Aviation Project. I would like to thank Matt for
making epoxy-amine networks and Stephen Foster for rheological experiments of
polyols. I am also grateful to Brian Olson for his help in PALS training and to Grace
Chigwada for her help in chemical synthesis and characterization.
I would like to acknowledge the faculty and staff in Polymer Science for their
support in everything I have asked. I would also like to extend thanks to Andreas Plagge,
Erin Price, Jody Wiggins and Beverly McNeese for their help. I thank my fellow graduate
students and my first year class for their friendship and support. Finally, I thank all the
close friends I have made in the program for their support and for the great times we had
together.
Most of all I would like to thank my family for always being there to love,
support and encourage me even if they think I should have been out of school by now.
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TABLE OF CONTENTS
ABSTRACT…………………………………………………………………………………….....i
ACKNOWLEDGEMENTS…………………………………………………………………...….iii
LIST OF ILLUSTRATIONS…………………………………………………………………….vii
LIST OF TABLES…………………………………………………………………………........xiv
LIST OF EQUATIONS………………………………………………………………………….xv
CHAPTER
I. FREE VOLUME AND RELATED PROPERTIES IN GLASSY POLYMERS
…………………...………………………………………………………………...1
Introduction
Estimation of Free Volume in Polymers
Effect of Free Volume on Physical Properties of Glassy Polymers
Factors Affecting Free Volume in Polymers
References

II. FREE VOLUME AND RELATED PROPERTIES OF ISOMERIC LINEAR
POLYESTERS AND EPOXY-AMINE NETWORKS…………………..……..30
Abstract
Introduction
Experimental
Results and Discussion
Conclusions
References
III. WATER INGRESS BEHAVIOR IN CROSSLINKED EPOXY-AMINE
NETWORKS: EFFECT OF FREE VOLUME EPOXY FUNCTIONALITY AND
CURING CYCLE…………………………………………………...…………...83
v
Abstract
Introduction
Experimental
Results and Discussion
Conclusions
References
IV. FREE VOLUME BEHAVIOR OF HYPERBRANCHED POLYESTER
POLYOLS: EXPERIMENT AND MODELLING…………………….……….129
Abstract
Introduction
Experimental
Results and Discussion
Conclusions
References
V. SUMMARY AND FUTURE WORK………………………………………….174
References

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