Polymer Additives Effects on Structure and Dynamics

166 Pages·2016·2.12 MB·English

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Doctoral Dissertations Graduate School
8-2015
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Adam Eugene Imel
University of Tennessee - Knoxville, [email protected]
Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss
Part of the Polymer Chemistry Commons
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Imel, Adam Eugene, "Polymer Additives Effects on Structure and Dynamics. " PhD diss., University of
Tennessee, 2015.
https://trace.tennessee.edu/utk_graddiss/3426
This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee
Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized
administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact
[email protected].
To the Graduate Council:
I am submitting herewith a dissertation written by Adam Eugene Imel entitled "Polymer
Additives Effects on Structure and Dynamics." I have examined the final electronic copy of this
dissertation for form and content and recommend that it be accepted in partial fulfillment of the
requirements for the degree of Doctor of Philosophy, with a major in Chemistry.
Mark D. Dadmun, Major Professor
We have read this dissertation and recommend its acceptance:
Jimmy W. Mays, Charles S. Feigerle, Thomas A. Zawodzinski
Accepted for the Council:
Carolyn R. Hodges
Vice Provost and Dean of the Graduate School
(Original signatures are on file with official student records.)
Polymer Additives Effects on Structure and Dynamics

A Dissertation Presented for the
Doctor of Philosophy
Degree
The University of Tennessee, Knoxville

Adam Eugene Imel
August 2015
Copyright © 2015 by Adam Imel.
All rights reserved.

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DEDICATION

This work is dedicated to my loving wife Megan Imel for her love and
understanding especially after putting up with me every day. I would also like to dedicate
this to my mother Janice Imel, my father Gene Imel, and my sisters Lauren Davey and
Tiffany Carroll for their love and support through the years.

“If you don't build your dream someone will hire you to help build theirs.”
Tony A. Gaskins Jr.
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ACKNOWLEDGEMENTS

The work presented in this dissertation would not have been possible without the
technical guidance provided by Professor Mark D. Dadmun. I would like to thank my
committee members Dr. Jimmy Mays, Dr. Charles Feigerle, and Dr. Tom Zawodzinski for
their time and help. I am thankful to all of my colleagues in the lab, especially Dr. Lesley
Thompson, Mr. Eddy Duranty, Mr. Brad Miller, and Mr. Brian Morgan for their
companionship. I am grateful to Dr. Wade Holley and Dr. Jimmy Mays for the synthetic
contributions to this work. I would like to thank Mr. Tom Malmgren for the conversations
and instrument help in the PCL. Finally, I am also grateful for the collaborations with Dr.
Alexei Sokolov and Dr. Jimmy Mays and their groups on other projects that helped me
learn and grow as a scientist.

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ABSTRACT

This dissertation presents work that expands the understanding of the effect
additives have on the structure and dynamics of a polymer matrix. Polymer additives are
molecules, nanoparticles or fibers that are added to a polymer to modify the properties of
the host polymer. Due to the vast amount of additives available, our studies were limited
to C (C60), soft polystyrene nanoparticles, and poly(ethylene oxide).
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The first part of this project examined the influence that C nanoparticles have on
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the assembly of polyacrylonitrile using small angle and wide-angle x-ray scattering
techniques and viscometry. The addition of C (C60) to polyacrylonitrile has little effect
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to the chain dimensions while in solution but shift the crystalline morphology from
hexagonal packing to an orthorhombic space group. Additionally, the C (C60)
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nanoparticle decreases the amount of crystallinity measured in the polymer
nanocomposites. This project provides insight into the use of non-covalent interactions
between a polymer and nanoparticle to produce a well-dispersed nanocomposite.
The next part of the project focuses on polystyrene center of mass diffusion in the
presence of soft polystyrene nanoparticles. The addition of the soft nanoparticles slowed
the matrix polymer diffusion when the nanoparticles were larger or the same size as the
matrix polymer chains. Although when the nanoparticles were 3 times smaller than the
matrix polymer chains the nanoparticles increased the diffusion of the host polymer chains.
Additionally, it was shown that the nanoparticles are not stationary, rather that the diffusion
of the nanoparticles is best described by the slow mode theory of diffusion.
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Finally, poly(ethylene oxide) was studied as an additive to lignin solutions, which
mimic the beginning production stages of lignin-based carbon fibers. The study focuses
on the influence that poly(ethylene oxide) has on the self-assembly of lignin while in
solution. The cylindrical structure of the lignin molecules is isotopically extended along
the length of the cylinder with the addition of poly(ethylene oxide) to varying magnitudes
depending on the source of the lignin. This work gives insight into the best starting
conditions for lignin-based carbon fiber that can maximize the properties of the final
product.

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TABLE OF CONTENTS

Chapter 1: Introduction ............................................................................................ 1
Polymer Additives ............................................................................................... 2
Mechanical Additives ....................................................................................... 3
Surface Additives ............................................................................................. 4
Chemical Additives .......................................................................................... 5
Aesthetic Additives .......................................................................................... 7
Processing Additives ........................................................................................ 7
Buckminsterfullerene (C60) ................................................................................... 9
Soft Polystyrene Nanoparticles ............................................................................ 13
Additives in the Production of Lignin based carbon fibers ...................................... 16
Summary .......................................................................................................... 20
Chapter 2: The Impact of Fullerenes on the Ordering of Polyacrylonitrile during
Nanocomposite Formation ...................................................................................... 22
Introduction....................................................................................................... 23
Methods / Experimental ...................................................................................... 26
Chemicals. ..................................................................................................... 26
Sample Preparation. ........................................................................................ 27
Viscosity. ...................................................................................................... 27
X-ray Scattering. ............................................................................................ 28
Results .............................................................................................................. 28
Viscosity. ...................................................................................................... 28
X-ray Diffraction. ........................................................................................... 31
Small-Angle X-ray Scattering: ......................................................................... 39
Discussion ........................................................................................................ 42
Conclusion ........................................................................................................ 44
Chapter 3: The Diffusion of Linear Polystyrene in the Presence of Soft Nanoparticles .. 46
Introduction....................................................................................................... 47
Experimental Section ......................................................................................... 51
Results .............................................................................................................. 56
Discussion ........................................................................................................ 61
Diffusion of Polystyrene where Rg,polymer ≤ Rg,NP ................................................ 67
Diffusion of Polystyrene where Rg,polymer > Rg,NP ................................................ 75
Importance of the Rg, polymer/ Rg, NP ratio ............................................................. 82
Conclusion ........................................................................................................ 83
Chapter 4: A Novel Method to Determine the Tracer Diffusion Coefficient of Soft
Nanoparticles Using Neutron Reflectivity ................................................................ 85
Introduction....................................................................................................... 86
Experimental ..................................................................................................... 87
Results and Discussion ....................................................................................... 90
Conclusion ...................................................................................................... 103
Chapter 5: The Impact of Poly(ethylene Oxide) on the Assembly of Lignin in Solution
.......................................................................................................................... 104
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Introduction..................................................................................................... 105
Experimental Section ....................................................................................... 109
Materials. .................................................................................................... 109
Results ............................................................................................................ 112
Discussion ...................................................................................................... 120
Conclusion ...................................................................................................... 125
Chapter 6: Conclusion & Future Work ................................................................... 128
Conclusion ...................................................................................................... 129
Polyacrylonitrile/C60 ..................................................................................... 130
Linear polystyrene diffusion in the presence of soft polystyrene nanoparticles .... 131
Diffusion of soft polystyrene nanoparticles ..................................................... 134
The addition of poly(ethylene oxide) to lignin ................................................. 135
Future Work .................................................................................................... 136
PAN/C60 ...................................................................................................... 137
Soft polystyrene nanoparticles ....................................................................... 137
Lignin based carbon fiber with PEO. .............................................................. 138
References .......................................................................................................... 139
VITA ................................................................................................................. 153

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