Table Of ContentPOLY AMIDE-GRAFT-ACRYLATE) INTERFACIAL COMPOUNDS
(
By
MICHAEL PEREZ ZAMORA
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1997
.
This dissertation is dedicated to all those who supported me
emotionally, physically, and financially throughout my
seemingly endless years of education; especially my wife
Karen, my parents Pablo and Sylvia, and my grandmother
Bella; and to the loving memory of Oscar Zamora and Manuel
Leon
.
ACKNOWLEDGMENTS
I cannot express enough gratitude and appreciation to
my advisor and doctoral committee chairman, Dr. Anthony
Brennan, for his years of teaching, guidance and support in
areas that extended well beyond my academic endeavors. I
would also like to express sincere thanks to the members of
my supervisory committee for their advice and teaching: Dr.
Jim Adair, Dr. Chris Batich, Dr. Eugene Goldberg, and Dr.
Ken Wagener.
I consider this experience substantially enriched by
the support of my colleagues. Whether there was
collaboration, debate or simply encouragement, it would have
been endlessly more difficult without the following: Dr.
Michael Antonell, Dr. Drew Amery, Craig Habeger, Jeff
Kerchner, Dr. James Marotta, Jeremy Mehlem, Dr. Rodrigo
Orefice, Luxsamee Plangsmangas, Mark Schwarz, and Dr. Chris
Widenhouse
Special thanks are extended to Arthur Gavrin for his
assistance with NMR spectroscopy and for the lively
discussions in his short time here, and Ananth Naman and Dr.
Rob Chodelka for their unwavering support and friendship. I
would be remiss not to mention Jesse Arnold and Tom Miller,
my colleagues of five years with whom I have grown, matured,
iii
and learned. I will forever be appreciative of our
continuous discussions, debates, and collaboration as well
as their undying support.
:iv
TABLE OF CONTENTS
ACKNOWLEDGMENTS iii
LIST OF TABLES viii
LIST OF FIGURES ix
ABSTRACT xiii
1. 1I.N1T.ROPDoUlCyTI(OamNide-g-acrylate) Graft Copolymers 11
1.1.1. Macromonomers 1
1.1.2. Addition-Condensation Graft Copolymers 3
1.1.3. Applications 4
1.2. Offsetting Polymerization Shrinkage in Dental
Resins through the Incorporation of Maleic
Anhydride 5
2. 2B.A1C.KGGRrOaUfNtDCopolymers 78
2.1.1. Synthetic Routes to Graft Copolymers 8
2.1.1.1. Anionically polymerized macromonomers 9
2.1.1.2. Macromonomers through chain transfer
functionalization 9
2.1.1.3. Modeling chain transfer reaction 15
2.1.2. Polyamide Addition-Condensation Multiphase
Copolymers 19
2.1.2.1. Poly(amide-b-olefin) block copolymers.... 19
2.1.2.2. Poly(amide-g-olefin) graft copolymers.... 28
2.2. Polymerization Shrinkage in Dental Composites 35
2.2.1. History of Dental Composites 36
2.2.2. Reduction of Polymerization Shrinkage in
Dental Resins 39
2.2.3. Use of Anhydrides in Dental Applications 41
2.2.4. Filler Modification in the Reduction of
Overall Composite Shrinkage 42
3. 3M.A1T.ERMIaAtLeSriAaNlDsMETHODS 4444
3.1.1. Macromonomer Reactants 44
3.1.2. Graft Copolymer Reactants 45
3.1.3. Dental Monomers 45
3.2. Methods 46
3.2.1. Synthesis and Characterization of
Macromonomers 46
3.2.2. Synthesis and Characterization of Graft
Copolymers 49
3.2.3. Synthesis and Characterization of Anhydride
Modified Dental Resins 52
RESULTS AND DISCUSSION 55
4.1. Synthesis and Characterization of Amino Acid-
terminated Poly(acrylate) Macromonomers using
Chain Transfer Chemistry 55
4.1.1. Determination of an Appropriate Solvent
System 59
4.1.2. Preliminary Studies of the Effectiveness of
Cysteine as a Chain Transfer Agent in the
Polymerization of Butyl Acrylate 61
4.1.3. Determination of Chain Transfer Constant of
Cysteine in the Synthesis of Amino Acid-
terminated Poly(butyl acrylate) Macromonomers 75
4.1.4. Cysteine Chain Transfer in the Synthesis of
Amino Acid-terminated Poly(methyl
methacrylate octafluoropentyl methacrylate)
Macromonomers: 88
4.2. Polyamide-g-poly(acrylate) graft copolymers
from Amino Acid-terminated Macromonomers 99
4.2.1. Synthesis of Poly(amide-g-butyl acrylate) .... 99
4.2.2. Characterization of Graft Copolymers 104
4.2.3. Blends of Graft Copolymers with Nylon 6 139
4.3. Offsetting Polymerization Shrinkage in Dental
Resins through the Incorporation of Maleic
Anhydride 144
4.3.1. Copolymer Compositions 146
4.3.2. Copolymer Characterization 149
SUMMARY AND CONCLUSIONS 158
5.1. Chain Transfer Functionalization of
Poly(acrylates) and Poly(methacrylates) 161
5.1.1. Conclusions for Preliminary Evaluation of
Cysteine Chain Transfer Agent 161
5.1.2 Conclusions for Synthesis and
Characterization of Amino Acid-terminated
Poly(butyl acrylate) 162
5.1.3 Conclusions for Synthesis and
Characterization of Amino Acid-terminated
Poly(MMA-co-OFPMA) 162
5.2. Graft Copolymerizations of Macromonomers with
Polyamide Precursors 163
5.2.1. Conclusions for Synthesis of Poly(amide-g-
acrylate) Graft Copolymers 164
VI
5.2.2. Conclusions for Characterization of
Poly(amide-g-acrylate) Graft Copolymers 165
5.2.3. Conclusions for Mechanical Properties of
Nylon 6/Graft Copolymer Blends 166
5.3. Offsetting Polymerization Shrinkage in
Poly(dimethacrylate) Dental Resins 166
5.3.1. Conclusions for Characterization of Maleic
Anhydride-containing Dental Resins 167
5.3.2. Conclusions for Synthesis and
Characterization of Anhydride Copolymer with
PEMA 168
6. FUTURE WORK 169
6.1. Macromonomers and Graft Copolymers 169
6.1.1. Macromonomer Work 169
6.1.2. Graft Copolymers 170
6.2. Anhydride-containing Dental Resins 171
LIST OF REFERENCES 173
BIOGRAPHICAL SKETCH 181
Vll
LIST OF TABLES
TABLE page
4.1 Solvent determination for monomer and chain
transfer agent °0
4.2 Percent functionalization versus molar mass for
poly(butyl acrylate) macromonomers 87
4.3 Molar mass values of fluoroacrylate copolymers from
GPC 91
4.4 Percent weight loss from Soxhlet extraction for
polyamide graft copolymers 105
4.5 Chemical composition of purified graft copolymers from
elemental analysis and NMR 137
4.6 Inherent viscosities of polyamide graft copolymers. 138
4.7 Tensile properties of nylon 6 blends 140
4.8 Experimental matrix of dental monomer compositions. 148
4.9 PEMA-maleic anhydride monomer compositions 149
4.10 EWC of maleic anhydride dental resins 150
4.11 Residual weight gain, anhydride incorporation and post
polymerization expansion of maleic anhydride dental
resins 151
4.12 Glass transition temperatures and composition of PEMA-
maleic anhydride copolymers 155
4.13 Molar mass averages from GPC for PEMA-anhydride
copolymers 157
6
LIST OF FIGURES
Figure page
1.1 Schematic illustration of general graft copolymer
structure 1
2.1. Mechanism of functionalization using chain transfer
agents 11
2.2. Schematic illustration of utilized chain transfer
agents and macromonomers thereof 16
2.3. Mechanism of block copolymer formation through
sequential polymerizations of vinyl monomer and
isocyanates 21
2.4. Reaction schematic for macroinitiator formation and
subsequent anionic block polymerization of caprolactam.
23
2.5 Reaction schematic of block copolymerization initiated
by nitrosated polyamide macroinitiators 25
2. bRleoaccktiocnoposlcyhmeemratitcheroefofAIBN containing polyamide and 27
2.7 Reaction schematic of in situ graft copolymer formation
from glycidyl methacrylate copolymers 31
2.8 Reaction schematic of in situ graft copolymer formation
from maleic anhydride modified polyolefins copolymers..
33
2.9 Mechanism of ring opening polymerization of spiro
orthocarbonate monomers 40
4.1. Mechanism of functionalization using chain transfer
reactions 57
4.2 Schematic of ideal amino acid functionalization during
polymerization of butyl acrylate 62
1X
4.3 GPC results of preliminary butyl acrylate
polymerizations 64
4.4 DSC trace of side product 66
4.5 FTIR spectra of side product of cysteine modified
P(BA) 67
4.6 Comparison of FTIR spectra of side product with butyl
acrylate monomer 68
4.7 Reaction pathway of cysteine with acrylates 69
4.8 Structure and elemental analysis of side product. ... 70
4.9 Side reaction preventing complete chain transfer. ... 73
4.10 Effect of acidification on chain transfer
functionalization of poly(butyl acrylate) 76
4.11 GPC results of polymerizations of butyl acrylate
varying cysteine concentrations 80
4.12 Mayo plot for chain transfer constant determination for
cysteinerbutyl acrylate system 81
4.13 FTIR spectra of poly(butyl acrylate) and cysteine end-
c1.a2ppkegd/mop(1BAp)(BAm)acrsoymnotnhoemseirze.d Muascinrgomo1n0o0m0e:r64:i1s btuhetyl
acrylate:cysteine:AIBN mole ratio 83
4.14 1H-NMR spectra of neat poly(butyl acrylate) 84
4.15 H-NMR spectra of 1.2kg/mo1 cysteine modified
poly(butyl acrylate) 85
4.16 13C-NMR spectra of 1.2kg/mol cysteine modified
poly(butyl acrylate) 86
4.17 Chemical structure of fluoroacrylate copolymer 90
4.18 GPC result of chain transfer polymerizations of
fluoroacrylate copolymers 91
4.19 Comparison of effectiveness of chain transfer for p(BA)
and fluoroacrylate copolymer 93
4.20 xH-NMR spectra of MMA-OFPMA macromonomer 95
