Table Of ContentRubber to Rubber Adhesion
Scrivener Publishing
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Adhesion and Adhesives: Fundamental and Applied Aspects
The topics to be covered include, but not limited to, basic and theoretical aspects
of adhesion; modeling of adhesion phenomena; mechanisms of adhesion; surface
and interfacial analysis and characterization; unraveling of events at interfaces;
characterization of interphases; adhesion of thin films and coatings; adhesion
aspects in reinforced composites; formation, characterization and durability of
adhesive joints; surface preparation methods; polymer surface m odification;
biological adhesion; particle adhesion; adhesion of metallized plastics; a dhesion of
diamond-like films; adhesion promoters; contact angle, wettability and adhesion;
superhydrophobicity and superhydrophilicity. With regards to adhesives, the Series
will include, but not limited to, green adhesives; novel and high-p erformance
adhesives; and medical adhesive applications.
Series Editor: Dr. K.L. Mittal
P.O. Box 1280, Hopewell Junction, NY 12533, USA
Email: [email protected]
Publishers at Scrivener
Martin Scrivener ([email protected])
Phillip Carmical ([email protected])
Rubber to Rubber Adhesion
Dinesh K. Kotnees
Department of Metallurgical and Materials Engineering, Indian Institute
of Technology Patna (IIT Patna), India
and
Anil K. Bhowmick
Department of Chemical and Biomolecular Engineering, The University
of Houston, USA
This edition first published 2021 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA
and Scrivener Publishing LLC, 100 Cummings Center, Suite 541J, Beverly, MA 01915, USA
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Library of Congress Cataloging-in-Publication Data
ISBN 978-1-119-76889-0
Cover image: Pixabay.Com
Cover design by Russell Richardson
Set in size of 11pt and Minion Pro by Manila Typesetting Company, Makati, Philippines
Printed in the USA
10 9 8 7 6 5 4 3 2 1
To
K. Malathi and N. Kotnees
Asmit Bhowmick
Kundakali Bhowmick
Our students and mentors
Contents
Foreword xv
Preface xvii
1 Introduction to Rubber 1
1.1 History 1
1.2 What is a Rubber? 3
1.3 What is the Structure of Rubber? 5
1.4 Why is Rubber Chosen Over Other Materials? 9
1.5 Brief Outline of Preparation of Rubber 10
1.6 Types of Rubber 13
1.6.1 Natural Rubber (NR) 14
1.6.2 Styrene - Butadiene Rubber (SBR) 14
1.6.3 Polybutadiene Rubber (BR) 15
1.6.4 Nitrile Rubber (NBR) and Hydrogenated
Nitrile Butadiene Rubber (HNBR) 15
1.6.5 Ethylene Propylene Rubber (EPDM/EPM) 16
1.6.6 Chloroprene Rubber (CR) 16
1.6.7 Butyl Rubber (IIR) 16
1.7 Compounding of Rubbers 17
1.7.1 Rubbers 17
1.7.2 Vulcanizing Agents 20
1.7.3 Accelerator and Accelerator-Activators 21
1.7.4 Age Resistors 21
1.7.5 Fillers 23
1.7.6 Processing Aid 23
1.7.7 Miscellaneous Ingredients 24
1.8 The Processes of the Rubber Industry 25
1.9 Why is Adhesion Important in Rubber Science? 28
References 29
vii
viii Contents
2 Important Physical Properties for Understanding Rubber
Adhesion and Measurements of Rubber Adhesion 31
2.1 Molecular Weight of Polymer 33
2.1.1 Definition 33
2.1.1.1 Number Average Molecular Weight (M ) 33
n
2.1.1.2 Weight Average Molecular Weight (M ) 34
w
2.1.1.3 Z-Average Molecular Weight (M) and
z
Viscosity Average Molecular Weight (M) 34
v
2.1.1.4 Molecular Weight Distribution (MWD) 35
2.1.2 Determination of Molecular Weight and MWD 36
2.1.2.1 GPC 36
2.1.2.2 Viscosity and Light Scattering Methods 37
2.1.2.3 Use of 1H NMR Spectroscopy in Polymer
Molecular Weight Analysis 38
2.1.3 Relationship Between Adhesion and Molecular
Weight in Unvulcanized Rubber 39
References 40
2.2 Glass Transition Temperature 41
2.2.1 Introduction and Definition 41
2.2.2 Glass Transition and Thermodynamics 42
2.2.3 Factors on Which T Depends 44
g
2.2.3.1 Chain Flexibility 44
2.2.3.2 Bulky Side Group 44
2.2.3.3 Polar Effect 44
2.2.3.4 Monomer Structure and T 44
g
2.2.3.5 Configurational Effect 45
2.2.3.6 Effect of Crosslinks 46
2.2.3.7 T and Plasticizer 46
g
2.2.4 Determination of T 46
g
References 49
2.3 Solubility Parameter, Interaction Parameter and Interface 50
2.3.1 Solubility Parameter 50
2.3.2 Interaction Parameter 52
2.3.3 Interface 55
References 59
2.4 Spectroscopic Techniques 60
2.4.1 Introduction 60
2.4.2 Principle of FTIR Spectroscopy 61
2.4.3 Principle of Nuclear Magnetic Resonance (NMR)
Spectroscopy 64
2.4.4 Principle of X-Ray Photoelectron Spectroscopy (XPS) 66
Contents ix
2.4.5 Chemical Groups and Adhesion 70
References 71
2.5 Microscopy 73
2.5.1 Optical or Light Microscopy 73
2.5.2 Scanning Electron Microscopy (SEM) 74
2.5.2.1 Principle of SEM 74
2.5.2.2 Sample Preparation and Measurements 76
2.5.3 Transmission Electron Microscopy (TEM) 79
2.5.4 Atomic Force Microscopy (AFM) 80
2.5.4.1 Principle 81
2.5.4.2 Operational Modes 82
2.5.4.3 Detection Method 83
2.5.4.4 Imaging and Analysis 84
References 89
2.6 Contact Angle, Surface Energy and Surface Roughness 91
2.6.1 Contact Angle 91
2.6.1.1 Concepts 91
2.6.1.2 Measurements 92
2.6.2 Surface Energy 93
2.6.3 Work of Adhesion and Spreading Coefficient 99
2.6.4 Theoretical Adhesion and Practical Adhesion 101
2.6.5 Surface Roughness 101
2.6.5.1 Concepts 101
2.6.5.2 Measurements 103
References 108
2.7 Rheological Properties of Rubber 110
2.7.1 Definition 110
2.7.1.1 Shear Viscosity 110
2.7.1.2 Shear Stress 111
2.7.1.3 Shear Rate 111
2.7.1.4 Viscous and Elastic Components 111
2.7.2 Measurement of Viscosity and Elasticity 113
2.7.2.1 Capillary Viscometer/Rheometer 113
2.7.2.2 Rotational Rheometry/Viscometry 116
2.7.2.3 Oscillatory Rheometry 117
References 120
2.8 Curing and Crosslinking of Rubber 121
2.8.1 Concepts and Definitions 121
2.8.2 Measurements 123
2.8.3 Determination of Crosslink Density 126
2.8.3.1 Chemical Method 126
x Contents
2.8.3.2 Physical Method 128
2.8.4 Relationship Between Adhesion Strength
and Crosslinking 128
References 129
2.9 Mechanical Properties 131
2.9.1 Tensile Properties 131
2.9.1.1 Unvulcanized Rubber 131
2.9.1.2 Vulcanized Rubber 132
2.9.2 Tearing Energy/Tear Strength 134
2.9.3 Fatigue, Stress Relaxation and Creep of Rubber 137
References 142
2.10 Dynamical Mechanical Analysis (DMA) 144
2.10.1 Introduction 144
2.10.2 Operating Principles 145
2.10.3 Temperature Sweep Test Using DMA 148
2.10.4 Frequency Sweep Master Curves from Time-
Temperature Superposition (TTS) Using DMA 150
2.10.4.1 Terminal Relaxation Time ( ) from
te
Plateau and Terminal Zone 153
2.10.4.2 Self-Diffusion Coefficient (D) 154
2.10.4.3 Onset of Transition Zone
Relaxation Time ( ) 154
tr
2.10.4.4 Monomer Friction Coefficient,
MFC (ζ ) from Transition Zone 154
0
References 155
2.11 Diffusion and Adhesion 157
2.11.1 Concepts 157
2.11.2 Diffusion Theory of Adhesion 158
2.11.3 Methods to Identify Diffusion Across the Interface 158
2.11.4 Self-Diffusion Coefficient 159
2.11.5 Concept of Tack, Diffusion and Viscosity 161
2.11.6 Models Related to Diffusion of Polymers 164
2.11.6.1 Reptation Model 164
2.11.6.2 Model Theory of Crack Healing 165
References 168
2.12 Test Methods for Rubber to Rubber Adhesion
and Self-Healing 171
2.12.1 Unvulcanized Rubber Test 171
2.12.2 Vulcanized Rubber Test 178
2.12.3 Tests for Self-Healing 187
References 189
