Synthesis, Characterization and Properties of Semi-aromatic Polyamide Thermosets

149 Pages·2017·4.08 MB·English

Delft University of Technology

Synthesis, Characterization and Properties of Semi-aromatic Polyamide Thermosets
Li, Ming
DOI
10.4233/uuid:8e3dd0ce-5269-4b53-8cdf-00cd3cb87eed
Publication date
2017
Document Version
Final published version
Citation (APA)
Li, M. (2017). Synthesis, Characterization and Properties of Semi-aromatic Polyamide Thermosets.
https://doi.org/10.4233/uuid:8e3dd0ce-5269-4b53-8cdf-00cd3cb87eed
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Synthesis, Characterization and Properties
of
Semi-aromatic Polyamide Thermosets

Proefschrift

ter verkrijging van de graad van doctor
aan de Technische Universiteit Delft,
op gezag van de Rector Magnificus Prof. ir. K. C. A. M. Luyben,
voorzitter van het College voor Promoties,
in het openbaar te verdedigen op
maandag 22 mei 2017 om 12:30 uur

door

Ming LI

Master of Science in Materials Science
Shanghai Jiao Tong University, Shanghai, China
geboren te Hebei, China
Dit proefschrift is goedgekeurd door de promotor:
Prof. dr. T. J. Dingemans

Samenstelling promotiecommissie:
Rector Magnificus voorzitter
Prof. dr. T.J. Dingemans Technische Universiteit Delft, promotor

Independent members:
Prof. dr. C.E. Koning Technische Universiteit Eindhoven
Dr. R. Rulkens DSM
Prof. dr. W.A. Groen Technische Universiteit Delft
Prof. dr. S.J. Picken Technische Universiteit Delft
Prof. dr. E.J.R. Sudhölter Technische Universiteit Delft
Prof. dr. ir. S. van der Zwaag Technische Universiteit Delft

The research carried out in this thesis is funded by the Dutch Polymer Institute (DPI), postbus
902, 5600 AX Eindhoven, Project #743.

ISBN: 978-94-6186-805-3
Copyright © 2017 by Ming Li
[email protected]

All rights reserved. No part of the materials protected by this copyright notice may be
reproduced or utilized in any form or by any means, electronic or mechanical, including
photocopying, recording or by any information storage and retrieval system, without
written permission from the author.

Published by: Gildeprint
CONTENTS

CHAPTER 1 INTRODUCTION .................................................................................. 1

1.1 POLYAMIDES ................................................................................................... 2
1.2 SEMI-AROMATIC POLYAMIDES ............................................................................ 2
1.2.1 MONOMER COMPOSITION OF SEMI-AROMATIC POLYAMIDES ...................................... 2
1.2.2 SEMI-CRYSTALLINE POLYPHTHALAMIDES ................................................................. 4
1.2.3 AMORPHOUS POLYPHTHALAMIDES ......................................................................... 7
1.3 POLY(DECAMETHYLENE TEREPHTHALAMIDE) (PA 10T) ............................................. 9
1.4 POLYAMIDE THERMOSETS ................................................................................ 11
1.4.1 IONIZING IRRADIATION ....................................................................................... 11
1.4.2 THERMAL CURING ............................................................................................. 11
1.5 SCOPE AND OUTLINE OF THE THESIS .................................................................... 14
1.6 REFERENCES .................................................................................................. 15
CHAPTER 2 SOLUTION POLYMERIZATION OF SEMI-AROMATIC POLYAMIDE PA
10T ...................................................................................................... 19
2.1 INTRODUCTION .............................................................................................. 20
2.2 EXPERIMENTAL .............................................................................................. 21
2.2.1 MATERIALS ...................................................................................................... 21
2.2.2 PA 10T POLYMERIZATION .................................................................................. 21
2.2.3 CHARACTERIZATION .......................................................................................... 22
2.3 OPTIMIZATION OF PA 10T SOLUTION POLYMERIZATION ......................................... 23
2.4 THERMAL PROPERTIES ..................................................................................... 26
2.4.1 TGA ............................................................................................................... 26
2.4.2 DSC ............................................................................................................... 26
2.5 WAXD STUDY OF SOLUTION-POLYMERIZED PA 10T .............................................. 30
2.6 THERMO-MECHANICAL PROPERTIES .................................................................... 33
2.7 CONCLUSIONS ............................................................................................... 35
2.8 REFERENCES .................................................................................................. 36
CHAPTER 3 SYNTHESIS AND CHARACTERIZATION OF REACTIVE PA 10T
OLIGOMERS AND THERMOSETS THEREOF ........................................................... 39
3.1 INTRODUCTION .............................................................................................. 40
3.2 SYNTHESIS AND CHARACTERIZATION ................................................................... 42
3.2.1 MATERIALS ...................................................................................................... 42
I
3.2.2 CHARACTERIZATION .......................................................................................... 42
3.2.3 SYNTHESIS OF REACTIVE END-CAPS ....................................................................... 43
3.2.4 REACTIVE MODEL COMPOUNDS ........................................................................... 45
3.2.5 SYNTHESIS OF REACTIVE PA 10T OLIGOMERS ......................................................... 48
3.2.6 PREPARATION OF THERMOSET FILMS .................................................................... 49
3.3 STUDY OF REACTIVE OLIGOMERS .......................................................................... 50
3.3.1 SOLUTION POLYMERIZATION ............................................................................... 50
3.3.2 THERMAL PROPERTIES ....................................................................................... 51
3.3.3 CURE BEHAVIOUR ............................................................................................. 53
3.3.4 NETWORK CHARACTERIZATION ........................................................................... 55
3.4 STUDY OF THERMOSET FILMS ............................................................................... 56
3.4.1 MELTING AND CRYSTALLIZATION .......................................................................... 56
3.4.2 WAXD ANALYSIS OF THERMOSET FILMS ................................................................ 58
3.4.3 THERMO-MECHANICAL PROPERTIES ..................................................................... 61
3.4.4 MECHANICAL PROPERTIES .................................................................................. 64
3.5 CONCLUSIONS .................................................................................................. 65
3.6 REFERENCES .................................................................................................... 66
CHAPTER 4 SYNTHESIS AND CHARACTERIZATION OF REACTIVE SIDE-GROUP
FUNCTIONALIZED COPOLYAMIDES AND THERMOSETS THEREOF ........................ 69
4.1 INTRODUCTION ............................................................................................. 70
4.2 EXPERIMENTAL .............................................................................................. 72
4.2.1 MATERIALS ...................................................................................................... 72
4.2.2 CHARACTERIZATION .......................................................................................... 73
4.2.3 SYNTHESIS OF PE COMONOMERS ......................................................................... 74
4.2.4 SYNTHESIS OF PE SIDE-GROUP FUNCTIONALIZED COPOLYAMIDES ............................... 76
4.2.5 PREPARATION OF THERMOSET FILMS .................................................................... 77
4.3 STUDY OF SIDE-GROUP FUNCTIONALIZED COPOLYAMIDES ........................................... 77
4.3.1 THERMAL BEHAVIOR OF PE COMONOMERS ........................................................... 77
4.3.2 COPOLYAMIDE STRUCTURES AND MOLECULAR WEIGHTS .......................................... 78
4.3.3 THERMAL PROPERTIES ....................................................................................... 81
4.4 THERMAL CURE OF COPOLYAMIDES ....................................................................... 84
4.4.1 POST-CONDENSATION ....................................................................................... 84
4.4.2 THERMAL CURE BEHAVIOR ..................................................................................... 87
4.5 MORPHOLOGY OF THE THERMOSET FILMS .............................................................. 88
4.5.1 MELTING AND CRYSTALLIZATION .......................................................................... 88
4.5.2 WAXD ANALYSIS OF THERMOSET FILMS ................................................................ 91
4.6 THERMO-MECHANICAL PROPERTIES ...................................................................... 93
4.7 MECHANICAL PROPERTIES ................................................................................... 94
4.8 APPROACHES TOWARDS PA 10T THERMOSETS ........................................................ 96
II
4.9 CONCLUSIONS .................................................................................................. 98
4.10 REFERENCES ................................................................................................... 99
CHAPTER 5 HIGH-TEMPERATURE SHAPE MEMORY BEHAVIOR OF PA 10T
THERMOSETS ................................................................................................... 101
5.1 INTRODUCTION ............................................................................................ 102
5.2 EXPERIMENTAL ............................................................................................ 106
5.2.1 MATERIALS .................................................................................................... 106
5.2.2 CHARACTERIZATION ........................................................................................ 107
5.3 SHAPE MEMORY EFFECT IN TORSION MODE ........................................................... 108
5.4 DUAL-SHAPE MEMORY BEHAVIOR ....................................................................... 110
5.5 TRIPLE-SHAPE MEMORY BEHAVIOR ...................................................................... 117
5.6 CONCLUSIONS ................................................................................................ 124
5.7 REFERENCES ................................................................................................... 125

SUMMARY ....................................................................................................... 127

SAMENVATTING ............................................................................................... 129

APPENDIX ......................................................................................................... 131

ACKNOWLEDGEMENTS ..................................................................................... 137

CURRICULUM VITAE ......................................................................................... 139

LIST OF PUBLICATIONS AND PRESENTATIONS ................................................... 141

III
IV
Chapter 1
Introduction
Chapter 1

1.1 Polyamides
Polyamides (PAs) remain a topic of interest because of their complex internal
structure and their commercial importance and versatility. The amide group, along
with its essential role in joining the monomers, dictates most of the properties of
PAs. Amide groups participate in hydrogen bonding, and consequently organize
polymer chains into ordered crystalline regions in most PAs, as shown in Figure 1.1.
The crystalline regions substantially augment the strength and heat-resistance of
PAs, leading to their use in demanding engineering applications.1

Figure 1.1 Structure of a semi-crystalline PA at different length scales. From left to
right: hydrogen bonding between amides, stacked hydrogen-bonded sheets,
crystalline and amorphous regions. Reproduced with permission from R. Rulkens, C.
Koning, 5.18 Chemistry and Technology of Polyamides, Polymer Science: A
Comprehensive Reference. Amsterdam: Elsevier, 2012.1

1.2 Semi-aromatic polyamides
1.2.1 Monomer composition of semi-aromatic polyamides
According to the composition of PA chains, synthetic polyamides are generally
classified into aliphatic, semi-aromatic and all-aromatic. Semi-aromatic PAs are
polyamides in which part of the monomer molecules contain an aromatic structural
unit. Semi-aromatic PAs were brought to market much later than aliphatic PAs, e.g.
PA 6 and PA 66 (Scheme 1.1). The commercialization of semi-aromatic PAs was
realized in 1980s to fulfil the requirements of engineering applications. Until now, a
substantial amount of semi-aromatic PA resins and composites with different
2
Introduction

compositions and formulations have been developed towards a wide range of
applications.

Scheme 1.1 Molecular structures and thermal transition temperatures of PA 6 and
PA 66.

As an intermediate between aliphatic and all-aromatic PAs, semi-aromatic PAs
combine the melt processability of aliphatic PAs and part of the thermal and
mechanical performance of fully aromatic PAs. Semi-aromatic PAs generally offer
higher stiffness and strength, greater thermal and dimensional stability over most
commonly used PA 6 and PA 66, leading to applications in complex electronic
devices, domestic appliances and automotive thermal management components.2, 3

Scheme 1.2 Examples of aromatic monomers in semi-aromatic polyamides.

Polyphthalamides (PPAs) are defined in ASTM D-5536 as a polyamide containing
aliphatic diamines and at least 55 mol% of terephthalic acid (TPA) or isophthalic
acid (IPA) or a combination of both (Scheme 1.2).4 PPAs form the most important
group of semi-aromatic PAs and were introduced into the market in the early 1990s
and hold a dominant position in the family of commercial semi-aromatic PAs. They
generally have low moisture absorption and moisture has little effect on their
mechanical and electrical properties.5 Most importantly, the carbonyl group of the
amide functionality conjugates with the aromatic ring, leading to enhanced
3