Rubber Technology - Compounding and Testing for Performance

Preface

Contents

Contributers

1 Rubber Compounding: Introduction, Definitions, and Available Resources

1.1 Introduction

1.2 The Recipe

1.3. Classification of Rubber Compounding Ingredients

1.4 Standard Abbreveiations for Compounding Ingredients

1.5 The Diversity of Rubber Recipes

1.6 Compatibility of Compounding Ingredients

1.7 Rubber Compounding Ingredients' Specifications

1.8 Raw Material Source Books

1.9 Key Source References for Formulations

1.10 Technical Organizations

1.11 Key Technical Journals and Trade Magazines

1.12 Regurarly Scheduled Technical Conferences

1.12.1 Regurarly Scheduled Courses

1.13 Web Sites Available

2. Compound Processing Characteristics and Testing

2.1 Introduction

2.2 Manufacturing Process

2.2.1 Two Roll Mill

2.2.2 Internal Mixers

2.2.3 Further Downstream Processing

2.2.4 Curing Process

2.2.5 Factory Problems

2.3 Processability Characteristics and Measurements

2.3.1 Viscosity

2.3.2 Shear Thinning

2.3.3 Elasticity

2.3.4 Time to Scorch

2.3.5 Cure Rate

2.3.6 Ultimate State of Cure

2.3.7 Reversion Resistance

2.3.8 Green Strength

2.3.9 Tackiness

2.3.10 Stickiness

2.3.11 Dispersion

2.3.12 Stock Storage Stability

2.3.13 Mis-Compounding

2.3.14 Cellular Rubber Blow Reaction

3 Vulcanizate Physical Properties, Performance Charecteristics, and Testing

3.1 Introduction

3.2 Density

3.3. Hardness

3.4 Tensile Stress-Strain

3.5 Stress-Strain Properties under Compression

3.6 Stress Strain Properties under Shear

3.7 Dynamic Properties

3.8 Low Temperature Properties

3.8.1 Brittle Point

3.8.2 Gehman Test

3.9 Stress Relevation, Creep, and Set

3.10 Permeability (Transmission)

3.11 Cured Adhesion

3.12 Tear Resistance

3.13 Degredation Properties

3.13.1 Flex Fatigue Resistance

3.13.2 Heat Resistance

3.13.3 Ozone Resistance

3.13.4 Weathering Resistance

3.13.5 Resitance of Liquids

3.13.6 Abrasion and Wear Resistance

4 Rubber Compound Economics

4.1. Introduction

4.2. Compound Cost Calculations

4.2.1 Specific Gravity

4.2.2 Cost/lb

4.2.3 Lb-Volume Cost

4.2.4 Part Cost

4.2.5 Conversion Factors for Calculating Part Cost

4.3 Measuring Specific Gravity (Density)

4.4 Cost Calculations

4.4.1 Base Compound

4.4.2 Same Ingredient Volume and Equal Cost

4.4.3 Low Cost/lb

4.4.4 High Specific Gravity

4.5 Compound Design and Cost

4.6 Reducing Compound Cost

4.6.1 High-Structure Carbon Blacks

4.6.2 White Compounds

4.6.3 Antioxidants/Antiozonants

4.6.4 Polymer Substitutions

5 The Technical Project Approach to Experimental Design and Compound Development

5.1 Introduction

5.2 Part 1: Steps in a Technical Project

5.2.1 Initial Action Required

5.2.2 Experimental Design

5.2.3 Conduct Measurements

5.2.4 Conduct Analysis and Evaluate Preliminary Modell

5.2.5 Prepare Report

5.3 Part 2: Using Experimental Designs

5.3.1 Screening Designs - Simple Treatment Comparisons

5.3.2 Screening Designs - Multifactor Experiments

5.3.3 Exploratory Designs - Multifactor Experiments

5.3.4 Evaluating the Statistical Significance of Effect Coefficients

6 Elastomer Selection

6.1 Overview

6.1.1 Commodity and General Purpose Elastomers

6.1.2 High Volume Specialty Elastomers

6.1.3 Low Volume Specialty Elastomers

6.1.4 Thermoplastic Elastomers

7 General Purpose Elastomers and Blends

7.1 Introduction

7.2 Natural Rubber and Polyisoprene

7.3 Polybutadiene

7.4 Copolymers and Terpolymers of Styrene, Butadiene, and Isoprene

7.5 Compounding with General Purpose Polymers

7.5.1 Polymer Characterization

7.5.2 Polymer Effect on Cure Rate

7.5.3 Polymer Effect on Stress-Strain

7.5.4 Hysteresis

7.5.5 Compability with SIR 10

7.5.6 Fatigue Properties

7.5.7 Compression Set

7.6 Conclusion

8 Specialty Elastomers

8.1 Introduction

8.2 Butyl Rubber

8.2.1 Introduction

8.2.2 Butyl Rubber Physical Properties

8.2.3 Butyl Rubber Properties, Vulcanization, and Applications

8.2.4 Gas Permeabiltity

8.2.5 Ozone and Weathering Resistance

8.2.6 Butyl Rubber Vulcanization

8.3 Halogenated Butyl Rubber

8.3.1 Introduction

8.3.2 Compounding Halobutyl and Star-Branched Halobutyl Rubbers

8.3.3 Processing Halobutyl Rubber

8.3.4 Halobutyl Rubber Vulcanization and Applications

8.3.5 Halobutyl Rubber General Applications

8.3.6 Cured Properties

8.3.7 Flex Resistance/Dynamic Properties

8.3.8 Compatibility with Other Elastomers

8.3.9. Halobutyl Rubber Compound Applications

8.4 EPM/EPDM

8.4.1 Introduction

8.4.2 Ethylene/Propylene Content

8.4.3 Diene Content

8.4.4 Rheology

8.5 Acrylonitrile-Butadiene Rubber

8.5.1 Introduction

8.5.2 Chemical and Physical Properties - Relating to Application

8.5.3 Polymer (Elastomer) Microstructure

8.5.4 Polymer (Elastomer) Macrostructure

8.5.5 Gel

8.5.6 Molecular Weight

8.5.7 Hot NBR

8.5.8 Crosslinked Hot NBR

8.5.9 Cold NBR

8.5.10 Carboxylated Nitrile (XNBR)

8.5.11 Bound Antioxidant NBR

8.6 Hydrogenated Nitrile Butadiene Elastomers

8.6.1 Introduction

8.6.2 Applications

8.6.3 Properties

8.6.4 Formulating

8.6.5 Processing

8.7 Polyacrylate Elastomers

8.7.1 Polymer Composition

8.7.2 Basic Compounding of Polyacrylate Polymers

8.7.3 Processing Guidelines

8.8 Polychloroprene (Neoprene)

8.8.1 Introduction

8.8.2 Basic Characteristics of Polychloroprene

8.8.3 Families of Neoprene

8.8.4 Neoprene 'G' Family

8.8.5 Neoprene 'W' Family

8.8.6 Neoprene 'T' Family

8.9 Chlorinated Polyethylene (CM)

8.9.1 Introduction

8.9.2 General Characteristics

8.10 Chlorosulfonated Polyethylene (CSM)

8.10.1 Introduction

8.10.2 General Purpose Types of Hypalon

8.10.3 Speciality Types of Hypalon

8.10.4 Unvulcanized Applications

8.11 Polyepichlorohydrin Elastomer

8.11.1 Introduction

8.11.2 Properties

8.11.3 Formulating

8.11.4 Nonlead Cure System

8.11.5 Adjustments

8.11.6 Processing

8.11.7 Internal Mixer - Procedure

8.11.8 Extrusion

8.11.9 Molding

8.12 Ethylene-Acrylic Elastomers

8.12.1 Introduction

8.12.2 Polymer Composition and Effect on Properties

8.12.3 Polymer Selection

8.13 Polynorbornene

8.13.1 Introduction

8.13.2 Applications

8.13.3 Compounding

8.13.4 Fillers

8.13.5 Oils/Plastizers

8.13.6 Cure System

8.13.7 Rebound/Resilience

8.13.8 Vibration Damping

8.13.9 Blends

8.13.10 Mixing and Processing

8.13.11 Calendaring

8.13.12 Extrusion

8.13.13 Molding

8.13.14 Summary

8.14 Fluoroelastometer

8.14.1 Introduction

8.14.2 Background

8.14.3 Applications

8.14.4 Viton Types

8.15 Silicone Elastomers

8.15.1 Introduction

8.15.2 Selection

8.15.3 Fillers

8.15.4 Antistructuring Agents

8.15.5 Heat Stabilizers

8.15.6 Peroxide Cures

8.15.7 Platinum Cures

8.15.8 RTV Cures

9 Polyurethane Elastomers

9.1 Introduction

9.2 Polyurethane Chemistry ans Morphology

9.3 Polyurethane Products

9.4 Cast Polyurethane Processing Overview

9.5. Molding Methods

9.5.1 Open Casting

9.5.2 Centrifugal Molding

9.5.3 Vacuum Casting

9.5.4 Compression Molding

9.5.5 Transfer Molding

9.5.6 Liquid Injection Molding (LIM)

9.5.7 Spraying

9.5.8 Moldless Rotational Casting

9.6. How to select a Polyurethane Elastomer

9.6.1 Types of Prepolymers

9.6.2 Types of Curatives

9.6.3 Processing Conditions

9.6.4 Additives

9.7 Comparison of Polyuethanes with Other Elastomers

9.7.1 Limitations of Polyuerthane Elastomers

9.8 Polyuerthane Selection Guidelines

9.8.1 Selecting a Polyuerthane Elastomer for a New Application

9.9 Millable Gums

9.10 Thermoplastic Polyuethanes

10 Thermoplastic Elastomers

10.1 Introduction

10.2 Position in Spectrum of Polymeric Materials

10.3 Classification of TPEs

10.3.1 Chemistry and Morphology

10.3.2 Styrenic Block Copolymers

10.3.3 Copolysters

10.3.4 Thermoplastic Polyurethanes

10.3.5 Polyamides

10.3.6 Thermoplastic Elastomeric Olefins

10.3.7 Thermoplastic Vulcanizates

10.4 TPEs and Thermoset Rubbers

10.5 Fabrication of TPEs

10.5.1 Economy of Thermoplastics Processing

10.5.2 Injection Molding

10.5.3 Extrusion

10.5.4 Blow Molding

10.5.5 Other Processing Methods

10.6 Acknowledgments

11 Recycled Rubber

11.1 Introduction

11.1.1 Tire Derived Fuel

11.1.2 Automotive Industry's Recycling Efforts

11.2 Recycling Methods

11.2.1 Reclaiming

11.2.2 Ambient Ground Rubber

11.2.3 Cyrogenic Ground Rubber

11.2.4 Wet Ground Rubber

11.2.5 Surface Treatment and Additives for Producing Recycled Rubber

11.3 Testing, Storage, and Characterization

11.3.1 Testing STandards

11.3.2 Material Storage

11.3.3 Moisture Content

11.3.4 Bulk Density

11.3.5 Chemical Analysis and Material Specifications

11.3.6 Particle Size and Distribution

12 Compounding with Carbon Black and Oil

12.1 Introduction: Carbon Black Affects Everything

12.2 Characterization of Carbon Black

12.2.1 The Particle, the Aggregate, and the Agglomerate

12.2.2 Surface Area, Structure, and Surface Acticity

12.2.3 Continents Other than Carbon (Impurities)

12.2.4 Pellets

12.2.5 ASTM Nomenclature

12.3 Handling Carbon Black

12.4 Mixing Carbon Black

12.4.1 Pellet Properties and Analyticals

12.4.2. Effect of Analytics on Dispersion

12.4.3 The Mixing Process

12.5 Subsequent Processability of the Company

12.6 Compounding Carbon Black

12.6.1 Optimum Loading

12.6.2 Importance of Dispersion

12.6.3 Carbon Black Compounding Tips

12.6.4 The Tire Industry's Tradeoffs

12.7 Hysteresis Reducing Tips

12.7.1 Radical Compounding

12.7.2 Lower Loadings of High Structure

12.7.3 Carbon-Silica Dual Phase Fillers

12.8 Practical Applications: Tire Examples

12.8.1. OE Passenger

12.8.2 Replacement Passenger-Tire

12.8.3 HP Passenger-Tire Treads

12.8.4 Medium Radial Truck Treads

12.8.5 Wire Coat or Skim Stocks

12.8.6 Innerliner Compounding

12.9 Major Tradcoffs for Industrial Rubber Products

12.9.1 Loading/Reinforcement/Cost

12.10 Compounding Tips: Industrial Rubber Products

12.10.1 Extrusion Profiles and Products

12.10.2 Molded Products

12.10.3 Hose Applications

12.11 Basics of Carbon Black Manufacture

12.11.1 History

12.11.2 The Oil-Furnace Process

13 Precipated Silicia and Non-Black Fillers

13.1 Introduction

13.2 Mineral Fillers

13.2.1 Calcium Carbonate

13.2.2 Baryte

13.2.3 Ground Crystalline SIlica

13.2.4 Biogenic Silica

13.2.5 Kaolin Clay

13.2.6 Talc

13.2.7 Alumina Trihydrate

13.3 Synthetic Fillers

13.3.1 Precipated Calcium Carbonate

13.3.2 Metal Oxides

13.3.3. Precipated Silica

13.3.4 Silicates

13.4 Surface Treatment

13.5 Compound Applications

13.5.1 General Compounding Principles

13.5.2 White Sidewall

13.5.3 Black Sidewall

13.5.4 Wire Coat

13.5.5 Innerliner

13.5.6 Tread

13.5.7 Specialty Applications

14 Ester Plasticizers and Processing Additives

14.1 Ester Plasticizers for Elastomers

14.1.1 Derivation

14.1.2 Philosophical

14.1.3 Applications

14.1.4 Applicatum Trends

14.2 Process Additives

14.2.1 Control of Viscosity

14.2.2 Mode of Action of Process Additives

14.2.3 Application of Process Additives

15 Sulfur Cure System

15.1 Introduction and Historical Background

15.2 Vulcanizing Agents

15.3. Activators

15.4. Accelerators

15.5 Conventional, Semi-Efficient

15.6 Retarders and Inhibitors

15.7 Recent Developments

16 Cures for Specialty Elastomers

16.1 Introduction

16.2 Cure System for EPDM

16.3 Cure Systems for Nitrile

16.4 Cure Systems for Polychloroprene

16.5 Cure Systems for Butyl and Halobutyl Rubber

17 Peroxide Cure Systems

17.1 Introduction

17.1.1 What is an Organic Peroxide?

17.1.2 Classes of Organic Peroxides

17.1.3 General Peroxide Selection Guidelines

17.2 Peroxide Used in Crosslinking

17.2.1 Diacyl Peroxides

17.2.2 Peroxyester and Monoperoxycarbonate Peroxides

17.2.3 Peroxyketal and Dialkyl Type Peroxides

17.2.4 Performance Characteristics of Type Peroxides

17.2.5 t-Amyl and t-Butyl Type Peroxides

17.2.6 Effect of Additives When Crosslinking with Peroxides

17.3 Role of Monomeric Coagnets in Peroxide Crosslinking

17.3.1 Crosslinking PE with Coagentsand Peroxides

17.3.2 Crosslinking EPDM with Coagents and Peroxides

17.3.3 Crosslinking HNBR with Coagents and Peroxides

17.4 Advantages and Disadvantages of Peroxide Crosslinking versus Sulfur Vulcanization

18 Tackifiying, Curing, and Reinforcing Resins

18.1 Introduction

18.2 Phenol-Formaldehyde Resins

18.2.1 Types of Phenol-Formaldehyde Resins

18.3 Methylene Donor Resins

18.4 Resorcinol-Based Resins

18.5 High Styrene Resins

18.6 Petroleum-Derived Resins

18.7 Wood-Derived Resins

19 Antidegredants

19.1 Introduction

19.2 Properties of Antidegredants

19.2.1 Discoloration and Staining

19.2.2 Volatility

19.2.3 Solubility and Migration

19.2.4 Chemical Stability

19.2.5 Physical Form

19.2.6 Antidegradant Concentration

19.3 Antidegradant Types

19.3.1 Non Staining, Non Discoloring Antioxidants

19.3.2 STaining/DIscoloring Antioxidants

19.3.3 Antioxidants

19.4 Examples of Antidegradant Activity

19.4.1 Oxidation Resistance

19.4.2 Effect of Antidegradants on Fatigue Life

19.4.3 Combinations of Antiozonants and Antioxidants

19.4.4 Resistance to Metal Poisoning

20 Compounding for Brass WIre Adhesion

20.1 Introduction

20.2 WIre Bonding Sytems

20.2.1 Cobalt

20.2.2 RF Resin Cobalt

20.3 The Adhesion Mechanism

20.4 Compound Ingredient Effects

20.4.1 Mixing

20.4.2 Testing

20.4.3 Regression Plots

20.5 Model NR Ply Compounds

20.5.1 Black Control Compound

20.5.2 Black/Cobalt Compund

20.5.3 Black/Cobalt/RF Resin

20.5.4 Black/Silica/Cobalt/RF Resin

20.6 Summary

21 Chemical Blowing Agents

21.1 Introduction

21.2 Terminology

21.2.1 Open Cell Structure

21.2.2 Closed Cell Structure

21.3 Inorganic Blowing Agents

21.4 Organic Blowing Agents

21.4.1 Azodicarbonamide

21.4.2 Sulfonyl Hydrazides

21.4.3 Dinitrosopentamethylenetetramine

21.5 Methods of Expansion

21.5.1 Low Pressure Molding Process

21.5.2 High Pressure Molding Process

21.5.3 Continuous Vulcanization

22 Flame Retardants

22.1 Introduction

22.2 Fire Standards, Testing, and Application

22.3 Commonly Used Flame Retardants in Elastomers

22.3.1 Aliphatic and Alicyclic Halogen Sources

22.3.2 Aromatic Halogen Sources

22.3.3 Synergists of Halogen Sources

22.4 Compounding and Dispersion Considerations

22.4.1 Polychloroprene

22.4.2 Chlorinated Polyethylene (CM)

22.4.3 Chlorosulfonated Polyethylene (CSM)

22.4.4 Ethylene-Propylene-Diene-Monomer (EPDM)

22.4.5 Styrene-Butadiene (SBR)

22.4.6 Nitrile-Butadiene Rubber (NBR) and Hydrogenated-Nitrile-Butadiene Rubber (HNBR)

22.4.7 Silicone Elastomer

22.4.8 Ethylene-Vinyl Acetate (EVM)

22.4.9 Ethylene-Propylene Elastomer (EPR)

22.4.10 Thermoplastic Elastomers (TPE)

23 Rubber Mixing

23.1 Introduction

23.2 History

23.3 Equipment

23.3.1 Mills

23.3.2 Internal Mixers

23.4 Mixing

23.4.1 Mill Mixing

23.4.2 Internal Mixer

23.5 Mixing Methods

23.5.1 Natural Rubber Mastication

23.5.2 Masterbatch

23.5.3 Phase Mixing

23.5.4 Single-Stage Mix

23.5.5 Single-Cycle Mix

23.5.6 Two-Stage Mix

23.5.7 Tandem Mix

23.5.8 Three-Stage Mix

23.5.9 Upside Down Mix

23.5.10 Variable Speed Mixing

23.5.11 Final Mix

23.5.12 Conntinous Mixing

23.5.13 E-SBR Carbon Black Masterbatch

23.5.14 Energy Mixing

Index