Adhesion and Adhesives Technology

Preface

Contents

1 Introduction

1.1 Introduction and Chapter Objectives

1.2 Basic Definitions

1.3 Advantages and Disadvantages of Adhesive Bonding

1.4 Uses of Adhesive Bonding in Modern Industry

1.5 Economics of Adhesive Technology

1.6 Literature and Other Sources of Information

1.7 Summary

References.

2 The Mechanical Properties of Materials as They Relate to Adhesion

2.1 Introduction

2.2 Definition of Mechanical Stresses for Materials Testing

2.3 Stress-Strain Plots and the Definition of Materials Property Parameters

2.3.1 Tensile Forces

2.3.2 Shear Forces

2.3.3 Strain Energy Density

2.4 Introduction to Linear Elastic Fracture Mechanics

2.5 Introduction to Rheology of Liquids

2.6 Introduction to Linear Viscoelasticity

2.7 An Application of Materials Properties and Mechanics: The Bending of Beams

2.8 Summary

Bibliography.

Problems and Review Questions.

3 Mechanical Tests of Adhesive Bond Performance

3.1 Introduction

3.2 Failure Modes and the Definition of Practical Adhesion

3.3 Tensile Testing of Adhesive Bonds

3.4 Shear Loading of Adhesive Bonds

3.4.1 The Standard Lap Shear Specimen

3.4.2 Variations on the Lap Shear Specimen

3.4.3 Specimen for Determining the True Shear Properties of an Adhesive

3.4.4 The Goland-Reissner Analysis of the Lap Shear Specimen [5]

3.5 Cleavage Loading of Adhesive Bonds

3.5.1 Cleavage or Fracture Specimens

3.5.1.1 Double Cantilever Beam Specimens

3.5.1.2 Linear Elastic Fracture Mechanics Applied to the Double Cantilever Beam Specimen

3.5.2 Blister Test

3.5.3 Compact Tension Test

3.5.4 Wedge Test

3.6 Peel Tests

3.6.1 Stress Analysis in a Peel Specimen

3.7 Summary

Bibliography.

References.

Problems and Review Questions.

4 The Basics of Intermolecular Forces and Surface Science

4.1 Introduction

4.2 Fundamental Forces

4.2.1 Electrostatic Forces

4.2.2 van der Waals Interactions

4.2.2.1 Dipole–Dipole Interactions

4.2.2.2 Dipole-Induced Dipole

4.2.2.3 Dispersion Forces

4.2.3 Interactions through Electron Pair Sharing

4.2.4 Repulsive Forces

4.3 Surface Forces and Surface Energy

4.4 Work of Cohesion and Adhesion

4.5 Methods of Measurement of Surface Energy and Related Parameters

4.5.1 Surface Tension

4.5.1.1 Drop Weight/Volume Method

4.5.1.2 Du Nuoy Tensiometer

4.5.2 Surface Energy of Solids

4.5.2.1 Contact Angle Methods

4.5.2.2 Contact Mechanics and Direct Measurement of Solid Surface Energy

4.6 Surface Thermodynamics and Predictions of Surface and Interfacial Tensions

4.6.1 The Good-Girifalco Relationship

4.6.2 The Fowkes Hypothesis and Fractional Polarity

4.6.3 The Zisman Plot

4.6.4 Modern Application of Contact Angle Measurements

4.7 Modern Methods of Surface Analysis

4.7.1 Modern Methods for Analysis of the Chemistry of Surfaces

4.7.2 Topological Methods of Surface Analysis

4.8 Summary

Bibliography.

References.

Problems and Review Questions.

5 Basic Physico/Chemical Properties of Polymers

5.1 Introduction

5.2 Basic Terminology

5.2.1 Monomers versus Polymers

5.2.2 Basic Types of Polymeric Materials

5.2.3 Molecular Weight

5.3 Thermal Transitions of Polymers

5.3.1 Measurement of Tg

5.4 Dynamic Mechanical Measurements and Viscoelasticity

5.4.1 Methods of Measurement of Dynamic Mechanical Properties

5.4.2 Examples of Dynamic Mechanical Data for Polymers

5.5 Time-Temperature Superposition

5.6 Summary

Bibliography.

References.

6 The Relationship of Surface Science and Adhesion Science

6.1 Introduction

6.2 Rationalizations of Adhesion Phenomena

6.3 Electrostatic Theory of Adhesion

6.4 Diffusion Theory of Adhesion

6.4.1 Diffusive Adhesive Bonding and Block Copolymers at Interfaces

6.5 Mechanical Interlocking and Adhesion

6.5.1 Kinetics of Pore Penetration

6.6 Wettability and Adhesion

6.7 Acid-Base Interactions at Interfaces

6.8 Covalent Bonding at Interfaces

6.8.1 Coupling Agents

6.9 The Relationship of Fundamental Forces of Adhesion and Practical Adhesion

6.10 The Weak Boundary Layer

6.11 Summary

Bibliography.

References.

Problems and Review Questions.

7 The Surface Preparation of Adherends for Adhesive Bonding

7.1 Introduction

7.2 Plastic Surface Preparation

7.2.1 Corona Discharge Treatment

7.2.1.1 Corona Discharge Treatment of Polyethylene

7.2.1.2 Corona Discharge Treatment of Polypropylene

7.2.1.3 Corona Discharge Treatment of Poly(ethylene terephthalate)

7.2.1.4 Corona Discharge Treatment of Other Materials

7.2.2 Flame Treatment

7.2.3 Plasma Treatment

7.2.3.1 Plasma Treatment of PE

7.2.3.2 Plasma Treatment of Other Substrates

7.2.4 Other Physical Treatment Methods of Polymer Surfaces

7.2.4.1 Treatments Using Ultraviolet Radiation

7.2.4.2 Other Vacuum Methods of Surface Preparation

7.2.5 Wet Chemical Methods of Treatment of Polymer Surfaces

7.2.5.1 Single Surface Chemical Functionalization and Chromic Acid Treatment of PE

7.2.5.2 Wet Chemical Surface Treatment of Poly(tetrafluoroethylene)

7.2.6 Priming of Polymer Surfaces

7.2.6.1 Priming of Polyolefins for Cyanoacrylates

7.2.6.2 Chlorinated Polyolefins

7.3 Metal Surface Preparation

7.3.1 Surface Preparation of Aluminum for Adhesive Bonding

7.3.1.1 The Forest Products Laboratory (FPL) Etch

7.4 Anodization Treatments for Adhesive Bonding of Aluminum

7.4.1 Mechanism of Anodization

7.4.2 Anodization Media

7.4.3 Phosphoric Acid Anodization in the Aerospace Industry

7.5 General Techniques for the Surface Preparation of Metals

7.5.1 Conversion Coatings

7.5.2 Abrasion

7.5.3 Electrochemical Methods for Treating Metals other than Aluminum

7.6 Summary

Bibliography.

References.

Problems and Review Questions.

8 The Chemistry and Physical Properties of Structural Adhesives

8.1 Introduction to Chapters 8–11 and 13

8.2 Introduction to Structural Adhesives

8.2.1 Physical Forms of Uncured Structural Adhesives

8.3 Chemistry of Base Resins Used in Structural Adhesives

8.3.1 Phenolics

8.3.2 Proteins

8.3.3 Epoxy Resins

8.3.3.1 Time-Temperature-Transformation Diagrams and the Cure of Epoxy Resins

8.3.4 Urethane Resins

8.3.5 Acrylics

8.3.6 High Temperature Performance Structural Adhesives

8.4 Formulation of Structural Adhesives for Optimum Performance

8.4.1 Formulation of Phenolic Resins

8.4.2 Epoxy Resins

8.4.3 Acrylics

8.4.4 High Temperature Performance Structural Adhesives

8.5 Summary

Bibliography.

References.

Problems and Review Questions.

9 Durability of Structural Adhesive Bonds

9.1 Introduction

9.2 Methods of Examining Durability of Structural Adhesive Bonds

9.3 Mechanisms of Durability Failure of Adhesive Bonds

9.4 Methods Used to Predict Durability

9.5 Summary

References.

10 The Chemistry and Physical Properties of Elastomer-Based Adhesives

10.1 Introduction

10.2 Pressure-sensitive Adhesives

10.2.1 Chemistry of the Base Resins Used in PSAs

10.2.2 Chemistry of Tackifiers

10.2.2.1 Natural Product Based Tackifiers

10.2.2.2 Petroleum Based Tackifiers

10.2.2.3 Other Tackifiers

10.2.3 Testing of Pressure-sensitive Adhesives

10.2.3.1 Measurements of Tack

10.2.3.2 Measurement of Peel

10.2.3.3 Measurement of Shear

10.2.4 Balance of Properties

10.2.5 PSA Performance Viewed as a Time Scale in Viscoelastic Response

10.2.6 PSA Viscoelasticity and Tack

10.2.7 PSA Peel and Viscoelasticity

10.2.8 Shear and Creep Behavior of PSAs

10.2.9 Summary

10.3 Rubber-Based, Contact Bond and other Elastomeric Adhesives

10.3.1 Formulation of RBAs

10.3.2 Base Polymers

10.3.3 Tackifiers

10.3.4 Pigments and Fillers

10.3.5 Crosslinking/Vulcanization of RBAs

10.3.6 Solvents

10.3.7 Elastomeric Adhesives, Sealants and Release Coatings Based upon Silicone Chemistry

10.4 Summary

Bibliography.

References.

Problems and Review Questions.

11 Thermoplastic, Pseudothermoplastic, and Other Adhesives

11.1 Introduction

11.2 Hot Melt Adhesives

11.2.1 Introduction

11.2.2 Polymer Physical Properties and Hot Melt Adhesives

11.2.3 Formulation of Hot Melt Adhesives

11.2.4 Synthetically Designed Hot Melt Adhesives

11.2.5 Curing Hot Melts

11.3 Polyvinyl Acetate-Based Adhesives

11.4 Polyvinyl Acetal Adhesives

11.5 Thermoplastic or Pseudo-thermoplastic Adhesives based upon Natural Products

11.5.1 Starches [7]

11.5.2 Cellulosics [8]

11.6 Summary

Bibliography.

References.

12 Adhesion in Biological Systems

12.1 Introduction

12.2 Adhesion in Microbiological Systems

12.3 Biofilm Formation

12.4 Growth Stages of Biofilms

12.4.1 Attachment to a Surface

12.4.2 Irreversible Attachment of Bacteria

12.4.3 Maturation Phase

12.4.4 Biofilm Dispersal

12.5 Maintenance or Elimination of Biofilms

12.6 Adhesion in the Cling Ability of the Tokai Gecko

12.6.1 Attempts to Artificially Produce the Gecko Features and Adhesive Ability

12.7 Summary

References.

13 The Basis for Adhesive Bond Design

13.1 Introduction

13.2 Chemistry and Mechanical Properties of Adhesives

13.3 Application Criteria

13.4 Interfaces and Surface Preparations

13.5 Miscellaneous Concerns

13.6 Basic Criteria for the Design of an Adhesive Bond

13.6.1 Hart-Smith Design Criteria for Double Lap Joints

13.7 Summary

References.

Problems and Review Questions.

Answer Key

Subject Index