Rubber Technology - Compounding & Testing For Performance

Author : John S Dick | Edition : 3rd | 2020 | 800 pages

A Practical Guide to Cost-Effective Formulating Of Rubber Compounds…

The latest third Edition of Rubber Technology: Compounding and Testing for Performance is a practical guide to cost-effective formulating of rubber compounds to achieve optimal processing and performance. It provides a thorough discussion of the principles of rubber compounding, rubber testing, and how various compound changes affect different properties and test measurements. Rubber compounding is discussed as a series of interdependent systems, such as the elastomer system, the filler-oil system, the cure system, among others. A holistic approach is used to show how changes in these different systems will affect specific compound properties.

Much attention is given to tradeoffs in properties and emphasis is placed on finding the best balance for compound cost, processing properties, and product performance. New in this third edition is the updated and extended section on silicone elastomers as well as the significantly expanded and newly written chapters on recycled rubber and precipitated silica and non-black fillers. A Practical Guide to Cost-Effective Formulating Of Rubber Compounds…

The latest third Edition of Rubber Technology: Compounding and Testing for Performance is a practical guide to cost-effective formulating of rubber compounds to achieve optimal processing and performance. It provides a thorough discussion of the principles of rubber compounding, rubber testing, and how various compound changes affect different properties and test measurements. Rubber compounding is discussed as a series of interdependent systems, such as the elastomer system, the filler-oil system, the cure system, among others. A holistic approach is used to show how changes in these different systems will affect specific compound properties. Much attention is given to tradeoffs in properties and emphasis is placed on finding the best balance for compound cost, processing properties, and product performance.

New in this third edition is the updated and extended section on silicone elastomers as well as the significantly expanded and newly written chapters on recycled rubber and precipitated silica and non-black fillers.

Table of Contents

1 Rubber Compounding: Introduction, Definitions, and

1.1 Introduction

1.2 The Recipe

1.3 Classification of Rubber Compounding Ingredients

1.4 Standard Abbreviations 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 Regularly Scheduled Technical Conferences

1.12.1 Regularly Scheduled Courses

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 Rotational Viscometers Capillary Rheometer Oscillating Rheometers Compression Plastimeters

2.3.2 Shear Thinning Shear Thinning by Capillary Rheometer Shear Thinning by Oscillating Rheometer

2.3.3 Elasticity Mooney Stress Relaxation Elasticity by Oscillating Rheometer Capillary Rheometer Die Swell Compression Plastimeter Elastic Recovery Direct Shrinkage Measurements

2.3.4 Time to Scorch Scorch by Rotational Viscometer Scorch by Oscillating Rheometer Scorch by Capillary Rheometer

2.3.5 Cure Rate Cure Rate by Rotational Viscometer Cure Times and Cure Rate by Oscillating Rheometer

2.3.6 Ultimate State of Cure Ring Testing Oscillating Rheometer

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 Characteristics, 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 Relaxation, Creep, and Set

3.10 Permeability (Transmission)

3.11 Cured Adhesion

3.12 Tear Resistance

3.13 Degradation 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 Resistance to 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 in3 and cost/lb cm3 and cost/kg ft3 and cost/lb cm3 and cost/lb Relative Costs Developing Conversion Factors

4.3 Measuring Specific Gravity (Density)

4.4 Cost Calculations

4.4.1 Base Compound 85

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 High Cost/High Specific Gravity Polymers Clear and Oil-Extended Polymer Replacements Carbon Black/Oil Masterbatches Replacing Free Mix Compounds Extrusion Productivity Vulcanization Productivity .

Appendix 4.1 . . . . . . . . . . . . . . . . 98

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 Planning Model Work, Time, and Cost Proposal

5.2.2 Experimental Design Selecting Variables or Factors Selecting Test Instruments and Procedures Developing a Response Model Selecting an Experimental Design

5.2.3 Conduct Measurements and Obtain Data

5.2.4 Conduct Analysis and Evaluate Preliminary Model

5.2.5 Prepare Report

5.3 Part 2: Using Experimental Designs

5.3.1 Screening Designs – Simple Treatment Comparisons Design C1 for Uniform Replication Conditions Design C1 for Non-Uniform Replication Conditions Design C2 for Multi-Treatment Comparisons

5.3.2 Screening Designs – Multifactor Experiments Two-Level Factorial Designs Analysis of the Designs Calculating the Effect Coefficients Reviewing Designs S1 to S11

5.3.3 Exploratory Designs – Multifactor Experiments

5.3.4 Evaluating the Statistical Significance of Effect Coefficients Evaluating Standard Errors for Effect Coefficients: Screening Designs Four-Factor Screening Design: An Example

Appendix 5.1 – A Catalog of Experimental Designs

6 Elastomer Selection

6.1 Overview

6.1.1 Commodity and General Purpose Elastomers Natural Rubber (NR) Styrene Butadiene Rubber (SBR) Polybutadiene Rubber (BR)

6.1.2 High-Volume Specialty Elastomers Polyisoprene (IR) Nitrile Rubber (NBR) Ethylene-Propylene-Diene (EPDM) Polychloroprene (CR) Butyl and Halogenated Butyl Elastomers Chlorinated and Chlorosulfonated Polyethylene

6.1.3 Low-Volume Specialty Elastomers Fluoroelastomers Silicone and Fluorosilicone Rubber Polyurethane Rubber Ethylene-Acrylic Rubber Polyacrylate Rubber 162 Epichlorohydrin Rubber Polyolefin Elastomers Polysulfide Rubber

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 and Effect on Mixing

7.5.2 Polymer Effect on Cure Rate

7.5.3 Polymer Effect on Stress–Strain

7.5.4 Hysteresis

7.5.5 Compatibility with SIR 10

7.5.6 Fatigue Properties

7.5.7 Compression Set

8 Specialty Elastomers

8.1 Introduction

8.2 Butyl Rubber

8.2.2 Butyl Rubber Physical Properties

8.2.3 Butyl Rubber Properties, Vulcanization, and Applications

8.2.4 Gas Permeability

8.2.5 Ozone and Weathering Resistance

8.2.6 Butyl Rubber Vulcanization Accelerated Sulfur Vulcanization The Dioxime Cure The Resin Cure

8.3 Halogenated Butyl Rubber

8.3.2 Compounding Halobutyl and Star-Branched Halobutyl Rubbers Carbon Black Mineral Fillers Plasticizers Processing Aids

8.3.3 Processing Halobutyl Rubber Mixing Calendering Extrusion Molding

8.3.4 Halobutyl Rubber Vulcanization and Applications Straight Sulfur Cure Zinc Oxide Cure and Modifications Zinc-Free Cures Peroxide Cures Vulcanization through Bis-Alkylation Resin Cure Scorch Control Stability of Halobutyl Crosslinks

8.3.5 Halobutyl Rubber General Applications

8.3.6 Cured Properties Permeability Heat Resistance Resistance to Chemicals and Solvents

8.3.7 Flex Resistance/Dynamic Properties

8.3.8 Compatibility with Other Elastomers

8.3.9 Halobutyl Rubber Compound Applications Tire Innerliners Pharmaceutical Closures Heat Resistant Conveyor Belt


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 Acrylonitrile Content (ACN) Mooney Viscosity Emulsifier Stabilizer Coagulation

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)

8.9.2 General Characteristics

8.10 Chlorosulfonated Polyethylene (CSM)

8.10.1 Introduction

8.10.2 General Purpose Types of Hypalon

8.10.3 Specialty Types of Hypalon

8.10.4 Unvulcanized Applications

8.11 Polyepichlorohydrin Elastomer

8.11.2 Properties

8.11.3 Formulating

8.11.4 Nonlead Cure Systems

8.11.5 Adjustments

8.11.6 Processing

8.11.7 Internal Mixer – Procedure

8.11.8 Extrusion

8.11.9 Molding

Appendix 8.1 – List of Chemicals

Appendix 8.2 – List of Plasticizers

8.12 Ethylene-Acrylic Elastomers

8.12.2 Polymer Composition and Effect on Properties

8.12.3 Polymer Selection

8.13 Polynorbornene

8.13.2 Applications

8.13.3 Compounding

8.13.4 Fillers

8.13.5 Oils/Plasticizers

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 Mill Mixing Internal Mixers

8.13.11 Calendering

8.13.12 Extrusion

8.13.13 Molding

8.13.14 Summary

8.14 Fluoroelastomer (FKM)

8.14.1 Introduction

8.14.2 Background

8.14.3 Applications

8.14.4 VitonR Types

8.15 Silicone Elastomers

8.15.1 Introduction

8.15.2 Selection

8.15.3 Fillers

8.15.4 Anti-Structuring 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 and 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 . . . . . . 296

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 Polyurethanes with Other Elastomers

9.7.1 Limitations of Polyurethane Elastomers

9.8 Polyurethane Selection Guidelines

9.8.1 Selecting a Polyurethane Elastomer for a New Application

9.9 Millable Gums

9.10 Thermoplastic Polyurethanes

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 Copolyesters

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

11 Recycled Rubber

11.2 History

11.3 Production Methods

11.3.1 Reclaim Rubber Process

11.3.2 Rubber Powder via Ambient and Cryogenic Processes

11.3.3 Rubber Powder via Ultra-High Pressure Water Jet Milling

11.3.4 Treated or Functionalized Rubber Powder

11.4 Classification, Characterization, and Testing of Recycled Rubber Powders

11.4.1 Classification System

11.4.2 Testing Methods for Particle Size Determination ASTM D5644 Method A – The Ro-Tap Procedure ASTM D5644 Method B – Ultrasonic and Light Microscopy Technique Laser Particle Size Analysis Surface Area Determination Surface Characterization

11.5 Comparison of Ambient and Cryogenically Prepared Recycled Rubber Powder

11.6 Physical and Rheological Properties of Rubber Compounds Mixed with Recycled Rubber Powder

11.6.1 RRP Baseline Study

11.6.2 Addition Point of Recycled Rubber Powder

11.6.3 Sulfur–Accelerator Optimization with Recycled Rubber Powder

11.6.4 Weathering Resistance with Recycled Rubber Powder

11.6.5 Heat Aging Resistance of Recycled Rubber Powder Containing Optimized Recipe

11.6.6 Selecting the Appropriate Recycled Rubber Powder Particle Size/Surface Area

11.6.7 Use of Recycled Rubber Powder in Solution SBR/Silica-Silane Tire Tread

11.7 New Technology for Recycled Rubber

11.7.1 EkoDyneTM Test Results in a Carbon Black Model Compound

11.7.2 EkoDyneTM Test Results in a Silica-Silane Model Compound

11.8 Executive Summary

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 Activity

12.2.3 Constituents 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 (Also Called Colloidal Properties)

12.4.2 Effect of Analyticals on Dispersion

12.4.3 The Mixing Process

12.5 Subsequent Processability of the Compound

12.6 Compounding Carbon Black

12.6.1 Optimum Loading

12.6.2 Importance of Dispersion

12.6.3 Carbon Black Compounding Tips Hardness Processing Oil Other Vulcanizate Properties Vulcanizate Hysteresis

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 Carbon Blacks

12.7.3 Carbon-Silica Dual Phase Fillers

12.8 Practical Applications: Tire Examples

12.8.1 OE Passenger-Tire Treads

12.8.2 Replacement Passenger-Tire Treads

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 Tradeoffs 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 Precipitated Silica and Non-Black Fillers

13.1.1 General Properties and Costs of Non-Black Fillers

13.1.2 Use and Selection of Non-Black Fillers for Rubber Compounds

13.1.3 Factors Considered for Reinforcing Rubber with Fillers Filler Particle Size and Surface Area Filler Anisometry – Shape and Morphology Surface Activity and Surface Energy

13.2 Mineral Fillers

13.2.1 An Overview of the Most Commonly Used Non-Black Fillers Calcium Carbonate Clay

13.2.2 Other Mineral Fillers Talc Barite Mica Alumina Trihydrate (ATH)

13.3 Synthetic Silica

13.3.1 Precipitated Silica

13.3.2 Precipitated Silica Characterization Structure and Surface Chemistry Surface Area Pore Volume and Void Volume Void Volume Silica Dispersion and Silanization

13.3.3 Highly Dispersible Silica (HDS)

13.3.4 Rice Husk Silica

13.3.5 Silica Surface Treatment

13.3.6 Pre-treated Silica

13.3.7 Masterbatching

13.4 Non-Black Nanoparticles and Polymeric Nanocomposites

13.4.1 Nano-Precipitated CaCO3 (Ultrafine Precipitated CaCO3) Nano-CaCO3 Surface Modification and Their Use for Nano-Composites Application Examples of Nano-CaCO3 in Various Rubbers

13.4.2 Layered Silicates and Their Nanocomposites Organoclay (Organic Layer Silicate) –Montmorillonite Cationic Clays – Hectorite and Their Applications in Rubber Nanocomposites Anionic Clays – Layered Double Hydroxide (LDH) and Their Applications in Rubber


13.4.3 Polymeric Core-Shell Nanoparticles Synthesis of Core-Shell Polymeric Nanoparticles Reinforcement and Performance of Rubber Compounds by Adding Tailored Polymeric Core-Shell Nanoparticles

13.5 Applications of Non-Black Fillers in Selected Segments of the Rubber Industry

13.5.1 Tires Tread Compounds Innerliner Compound White Sidewall Compounds

13.5.2 Wires and Cables Rubbers for High Voltage Insulation

13.5.3 Automotive Hose

13.5.4 Shoe and Footwear Products

13.5.5 Silicone-Rubber Compounding

14 Ester Plasticizers and Processing Additives

14.1 Ester Plasticizers for Elastomers

14.1.1 Derivation

14.1.2 Philosophical

14.1.3 Applications Low-ACN Content NBR Neoprene Blend GN 88/WHV 12 Different Elastomers with the Same Plasticizer Medium Acrylonitrile-Content NBR Medium ACN NBR Medium-High ACN-Content NBR NBR/PVC Polyblends Ethylene Acrylic and Polyacrylate Elastomers Chlorosulfonated Polyethylene (CSM) Chlorinated Polyethylene (CPE)

14.1.4 Application Trends

14.2 Process Additives

14.2.1 Control of Viscosity Viscosity Control of Natural Rubber Viscosity Control of Synthetic Rubber

14.2.2 Mode of Action of Process Additives Surface Lubricants Process Additives for Homogenizing and Improving Filler Dispersion

14.2.3 Application of Process Additives

Appendix 14.1 – Common Esters for Rubber

Appendix 14.2 – Abbreviations and Definitions

15 Sulfur Cure Systems

15.1 Introduction and Historical Background

15.2 Vulcanizing Agents

15.3 Activators

15.4 Accelerators

15.5 Conventional, Semi-Efficient, and Efficient Cures

15.6 Retarders and Inhibitors

15.7 Recent Developments

16 Cures for Specialty Elastomers

16.2 Cure Systems 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

17.1.1 What is an Organic Peroxide?

17.1.2 Classes of Organic Peroxides

17.1.3 General Peroxide Selection Guidelines Half-Life Minimum Cure Time SADT (Self Accelerating Decomposition Temperature) Maximum Storage Temperature (MST) Energy of Peroxide Free Radicals Peroxide Polymer Masterbatches High Performance (HP) Peroxide Formulations for Improved Productivity

17.2 Peroxides 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 Dialkyl 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 Coagents in Peroxide Crosslinking

17.3.1 Crosslinking PE with Coagents and 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 Tackifying, Curing, and Reinforcing Resins

18.2 Phenol-Formaldehyde Resins

18.2.1 Types of Phenol-Formaldehyde Resins Reinforcing Resins Tackifying Resins Curing 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 Antidegradants

19.2 Properties of Antidegradants

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 Hindered Phenols Hindered “Bis” Phenols Substituted Hydroquinones Phosphites Organic Sulfur Compounds Hindered Amine and Nitroxyl Compounds

19.3.2 Staining/Discoloring Antioxidants Phenylnaphthylamines Dihydroquinolines Diphenylamine Derivatives Substituted Paraphenylenediamines (PPDs) Amine-based, “Bound-in” or “Polymer Bound” Antioxidants

19.3.3 Antiozonants Petroleum Waxes Nickel Dibutyldithiocarbamate (NBC) 6-Ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (ETMQ) Substituted Paraphenylenediamines (PPDs)

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 Systems

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 Carbon Black Zinc Oxide/Stearic Acid Sulfur/DCBS Cobalt RF Resin/HMMM Carbon Black/Silica Summary of Test Results

20.5 Model NR Ply Compounds 681

20.5.1 Black Control Compound

20.5.2 Black/Cobalt Compound

20.5.3 Black/Cobalt/RF Resin

20.5.4 Black/Silica/Cobalt/RF Resin

21 Chemical Blowing Agents

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 (ADC) Properties Activation Factors Affecting Performance Effect of Particle Size Effect of Temperature ADC Activation and Cell Size

21.4.2 Sulfonyl Hydrazides Properties Activation Applications

21.4.3 Dinitrosopentamethylenetetramine (DNPT) Properties Activation

21.5 Methods of Expansion

21.5.1 Low Pressure Molding Process

21.5.2 High Pressure Molding Process Precure Stage Final Cure Stage

21.5.3 Continuous Vulcanization (CV)

22 Flame Retardants

22.1 Introduction

22.2 Fire Standards, Testing, and Applications

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 Antimony Oxide Zinc Borate Phosphorus Compounds

22.3.4 Flame Retardant Fillers Alumina Trihydrate (ATH) Magnesium Hydroxide Calcium Carbonate . Clay, Talc, and Silica Carbon Black

22.4 Compounding and Dispersion Considerations

22.4.1 Polychloroprene (CR)

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

23.2 History

23.3 Equipment

23.3.1 Mills

23.3.2 Internal Mixers Tangential Rotor Type Intermeshing Rotor Type Variable Internal Clearance Mixer Continuous Mixers Extruders

23.4 Mixing .

23.4.1 Mill Mixing

23.4.2 Internal Mixer Batch Size Batch Conversion Factor Density and Cost Calculations Mixing Procedures Mixing Temperatures

23.5 Mixing Methods

23.5.1 Natural Rubber Mastication

23.5.2 Masterbatch Mixing

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 Mixing

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 Continuous Mixing

23.5.13 E-SBR Carbon Black Masterbatch

23.5.14 Energy Mixing