This first comprehensive overview of reactive extrusion technology for over a decade combines the views of contributors from both academia and industry who share their experiences and highlight possible applications and markets. They also provide updated information on the underlying chemical and physical concepts, summarizing recent developments in terms of the material and machinery used.
As a result, readers will find here a compilation of potential applications for reactive extrusion to access new and cost-effective polymeric materials, while using existing compounding machines.

Dr. rer. nat Gunter Beyer is Manager of the physical and chemical laboratories at Kabelwerk EUPEN AG (Belgium). He received his PhD in organic chemistry and photochemistry in 1984 from RWTH Aachen University (Germany) and started to work at Kabelwerk Eupen in the same year. Since 1996 he is responsible for the R&D activities for material development and heads the chemical-physical laboratory. With more than 30 years of experience in polymer science and applications, Dr. Beyer is regularly acting as chairman and speaker at many international conferences, especially in the field of flame retardancy, nanocomposites and polymer science. In 2003 and also in 2004 he received the Jack Spergel Memorial Award for his fundamental work on nanocomposites by organoclays and carbon nanotubes as new classes of flame retardants for polymers.

Professor Dr.-Ing. Christian Hopmann is Head of the Institute of Plastics Processing in Industry and the Skilled Crafts (Aachen, Germany) since 2011 and holds the Chair of Plastics Processing at the Faculty of Mechanical Engineering at RWTH Aachen University (Germany). Hopmann studied Mechanical Engineering at RWTH Aachen (Germany) and received his doctoral degree in 2000. From 2001 to 2004 he was Chief Engineer and Senior Vice Director of the Institute of Plastics Processing. In 2005, Hopmann started his industrial career at RKW AG Rheinische Kunststoffwerke (today: RKW SE), Europe's leading manufacturer of high quality polyethylene and polypropylene films, nonwovens and nets, being head of the Quality Management at RKW's site in Petersaurach (Germany). From 2006 to end of 2009 he was Head of Extrusion and thus responsible for the production of polyolefin films for hygiene, consumer packaging and industrial applications. From January 2010 to April 2011 he was Managing Director of RKW Sweden AB in Helsingborg (Sweden).

Preface xiii

List of Contributors xv

Part I Introduction 1

1 Introduction to Reactive Extrusion 3
Christian Hopmann, Maximilian Adamy, and Andreas Cohnen

References 9

Part II Introduction to Twin-Screw Extruder for Reactive Extrusion 11

2 The Co-rotating Twin-Screw Extruder for Reactive Extrusion 13
Frank Lechner

2.1 Introduction 13

2.2 Development and Key Figures of the Co-rotating Twin-Screw Extruder 14

2.3 Screw Elements 16

2.4 Co-rotating Twin-Screw Extruder Unit Operations 22

2.4.1 Feeding 23

2.4.2 Upstream Feeding 23

2.4.3 Downstream Feeding 24

2.4.4 Melting Mechanisms 24

2.4.5 Thermal Energy Transfer 24

2.4.6 Mechanical Energy Transfer 25

2.4.7 Mixing Mechanisms 25

2.4.8 Devolatilization/Degassing 25

2.4.9 Discharge 26

2.5 Suitability of Twin-Screw Extruders for Chemical Reactions 26

2.6 Processing of TPE-V 27

2.7 Polymerization of Thermoplastic Polyurethane (TPU) 29

2.8 Grafting of Maleic Anhydride on Polyolefines 31

2.9 Partial Glycolysis of PET 32

2.10 Peroxide Break-Down of Polypropylene 33

2.11 Summary 35

References 35

Part III Simulation and Modeling 37

3 Modeling of Twin Screw Reactive Extrusion: Challenges and Applications 39
Françoise Berzin and Bruno Vergnes

3.1 Introduction 39

3.1.1 Presentation of the Reactive Extrusion Process 39

3.1.2 Examples of Industrial Applications 40

3.1.3 Interest of Reactive Extrusion Process Modeling 41

3.2 Principles and Challenges of the Modeling 41

3.2.1 Twin Screw Flow Module 42

3.2.2 Kinetic Equations 44

3.2.3 Rheokinetic Model 44

3.2.4 Coupling 45

3.2.5 Open Problems and Remaining Challenges 45

3.3 Examples of Modeling 46

3.3.1 Esterification of EVA Copolymer 46

3.3.2 Controlled Degradation of Polypropylene 50

3.3.3 Polymerization of -Caprolactone 55

3.3.4 Starch Cationization 59

3.3.5 Optimization and Scale-up 61

3.4 Conclusion 65

References 66

4 Measurement and Modeling of Local Residence Time Distributions in a Twin-Screw Extruder 71
Xian-Ming Zhang, Lian-Fang Feng, and Guo-Hua Hu

4.1 Introduction 71

4.2 Measurement of the Global and Local RTD 72

4.2.1 Theory of RTD 72

4.2.2 In-line RTD Measuring System 73

4.2.3 Extruder and Screw Configurations 75

4.2.4 Performance of the In-line RTD Measuring System 76

4.2.5 Effects of Screw Speed and Feed Rate on RTD 77

4.2.6 Assessment of the Local RTD in the Kneading Disk Zone 79

4.3 Residence Time, Residence Revolution, and Residence Volume Distributions 81

4.3.1 Partial RTD, RRD, and RVD 82

4.3.2 Local RTD, RRD, and RVD 86

4.4 Modeling of Local Residence Time Distributions 88

4.4.1 Kinematic Modeling of Distributive Mixing 88

4.4.2 Numerical Simulation 89

4.4.3 Experimental Validation 92

4.4.4 Distributive Mixing Performance and Efficiency 93

4.5 Summary 97

References 98

5 In-process Measurements for Reactive Extrusion Monitoring and Control 101
José A. Covas

5.1 Introduction 101

5.2 Requirements of In-process Monitoring of Reactive Extrusion 103

5.3 In-process Optical Spectroscopy 111

5.4 In-process Rheometry 116

5.5 Conclusions 125

Acknowledgment 126

References 126

Part IV Synthesis Concepts 133

6 Exchange Reaction Mechanisms in the Reactive Extrusion of Condensation Polymers 135
Concetto Puglisi and Filippo Samperi

6.1 Introduction 135

6.2 Interchange Reaction in Polyester/Polyester Blends 138

6.3 Interchange Reaction in Polycarbonate/Polyester Blends 143

6.4 Interchange Reaction in Polyester/Polyamide Blends 148

6.5 Interchange Reaction in Polycarbonate/Polyamide Blends 155

6.6 Interchange Reaction in Polyamide/Polyamide Blends 159

6.7 Conclusions 166

References 167

7 In situ Synthesis of Inorganic and/or Organic Phases in Thermoplastic Polymers by Reactive Extrusion 179
Véronique Bounor-Legaré, Françoise Fenouillot, and Philippe Cassagnau

7.1 Introduction 179

7.2 Nanocomposites 179

7.2.1 Synthesis of in situ Nanocomposites 181

7.2.2 Some Specific Applications 183

7.2.2.1 Antibacterial Properties of PP/TiO 2 Nanocomposites 183

7.2.2.2 Flame-Retardant Properties 184

7.2.2.3 Protonic Conductivity 186

7.3 Polymerization of a Thermoplastic Minor Phase: Toward Blend Nanostructuration 188

7.4 Polymerization of a Thermoset Minor Phase Under Shear 196

7.4.1 Thermoplastic Polymer/Epoxy-Amine Miscible Blends 197

7.4.2 Examples of Stabilization of Thermoplastic Polymer/Epoxy-Amine Blends 202

7.4.3 Blends of Thermoplastic Polymer with Monomers Crosslinking via Radical Polymerization 202

7.5 Conclusion 203

References 204

8 Concept of (Reactive) Compatibilizer-Tracer for Emulsification Curve Build-up, Compatibilizer Selection, and Process Optimization of Immiscible Polymer Blends 209
Cai-Liang Zhang, Wei-Yun Ji, Lian-Fang Feng, and Guo-Hua Hu

8.1 Introduction 209

8.2 Emulsification Curves of Immiscible Polymer Blends in a Batch Mixer 210

8.3 Emulsification Curves of Immiscible Polymer Blends in a Twin-Screw Extruder Using the Concept of (Reactive) Compatibilizer 213

8.3.1 Synthesis of (Reactive) Compatibilizer-Tracers 213

8.3.2 Development of an In-line Fluorescence Measuring Device 214

8.3.3 Experimental Procedure for Emulsification Curve Build-up 216

8.3.4 Compatibilizer Selection Using the Concept of Compatibilizer-Tracer 219

8.3.5 Process Optimization Using the Concept of Compatibilizer-Tracer 220

8.3.5.1 Effect of Screw Speed 220

8.3.5.2 Effects of the Type of Mixer 221

8.3.6 Section Summary 221

8.4 Emulsification Curves of Reactive Immiscible Polymer Blends in a Twin-Screw Exturder 222

8.4.1 Reaction Kinetics between Reactive Functional Groups 222

8.4.2 (Non-reactive) Compatibilizers Versus Reactive Compatibilizers 223

8.4.3 An Example of Reactive Compatibilizer-Tracer 224

8.4.4 Assessment of the Morphology Development of Reactive Immiscible Polymer Blends Using the Concept of Reactive Compatibilizer 225

8.4.5 Emulsification Curve Build-up in a Twin-Screw Extruder Using the Concept of Reactive Compatibilizer-Tracer 229

8.4.6 Assessment of the Effects of Processing Parameters Using the Concept of Reactive Compatibilizer-Tracer 233

8.4.6.1 Effect of the Reactive Compatibilizer-Tracer Injection Location 233

8.4.6.2 Effect of the Blend Composition 235

8.4.6.3 Effect of the Geometry of Screw Elements 238

8.5 Conclusion 241

References 241

Part V Selected Examples of Synthesis 245

9 Nano-structuring of Polymer Blends by in situ Polymerization and in situ Compatibilization Processes 247
Cai-Liang Zhang, Lian-Fang Feng, and Guo-Hua Hu

9.1 Introduction 247

9.2 Morphology Development of Classical Immiscible Polymer Blending Processes 248

9.2.1 SolidLiquid Transition Stage 249

9.2.2 Melt Flow Stage 251

9.2.3 Effect of Compatibilizer 253

9.3 In situ Polymerization and in situ Compatibilization of Polymer Blends 255

9.3.1 Principles 255

9.3.2 Classical Polymer Blending Versus in situ Polymerization and in situ Compatibilization 255

9.3.3 Examples of Nano-structured Polymer Blends by in situ Polymerization and in situ Compatibilization 257

9.3.3.1 PP/PA6 Nano-blends 257

9.3.3.2 PPO/PA6 Nano-blends 264

9.3.3.3 PA6/CoreShell Blends 264

9.4 Summary 267

References 268

10 Reactive Comb Compatibilizers for Immiscible Polymer Blends 271
Yongjin Li, Wenyong Dong, and Hengti Wang

10.1 Introduction 271

10.2 Synthesis of Reactive Comb Polymers 272

10.3 Reactive Compatibilization of Immiscible Polymer Blends by Reactive Comb Polymers 274

10.3.1 PLLA/PVDF Blends Compatibilized by Reactive Comb Polymers 274

10.3.1.1 Comparison of the Compatibilization Efficiency of Reactive Linear and Reactive Comb Polymers 274

10.3.1.2 Effects of the Molecular Structures on the Compatibilization Efficiency of Reactive Comb Polymers 278

10.3.2 PLLA/ABS Blends Compatibilized by Reactive Comb Polymers 282

10.4 Immiscible Polymer Blends Compatiblized by Janus Nanomicelles 289

10.5 Conclusions and Further Remarks 293

References 293

11 Reactive Compounding of Highly Filled Flame Retardant Wire and Cable Compounds 299
Mario Neuenhaus and Andreas Niklaus

11.1 Introduction 299

11.2 Formulations and Ingredients 300

11.2.1 Typical Formulation and Variations for the Evaluation 300

11.2.2 Principle of Silane Crosslinking by Reactive Extrusion 301

11.2.3 Production of Aluminum Trihydroxide (ATH) 301

11.2.4 Mode of Action of Aluminum Trihydroxide 302

11.2.5 Selection of Suitable ATH Grades 303

11.3 Processing 306

11.3.1 Compounding Line 306

11.3.2 Compounding Process for Cross Linkable HFFR Products 308

11.3.2.1 Two-Step Compounding Process 308

11.3.2.2 One-Step Compounding Process 309

11.3.2.3 Advantages and Disadvantages of the Two Process Concepts (Two-Step vs One-Step) 313

11.4 Evaluation and Results on the Compound 314

11.4.1 Crosslinking Density 314

11.4.2 Mechanical Properties 315

11.4.3 Aging Performance 315

11.4.4 Fire Performance on Laboratory Scale 317

11.4.5 Results of the Non-Polar Compounds 318

11.5 Cable Trials 322

11.5.1 Fire Performance of Electrical Cables According to EN 50399 322

11.5.2 Burning Test on Experimental Cables According to EN 50399 323

11.6 Conclusions 328

References 329

12 Thermoplastic Vulcanizates (TPVs) by the Dynamic Vulcanization of Miscible or Highly Compatible Plastic/Rubber Blends 331
Yongjin Li and Yanchun Tang

12.1 Introduction 331

12.2 Morphological Development of TPVs from Immiscible Polymer Blends 333

12.3 TPVs from Miscible PVDF/ACM Blends 334

12.4 TPVs from Highly Compatible EVA/EVM Blends 338

12.5 Conclusions and Future Remarks 342

References 342

Part VI Selected Examples of Processing 345

13 Reactive Extrusion of Polyamide 6 with Integrated Multiple Melt Degassing 347
Christian Hopmann, Eike Klünker, Andreas Cohnen, and Maximilian Adamy

13.1 Introduction 347

13.2 Synthesis of Polyamide 6 347

13.2.1 Hydrolytic Polymerization of Polyamide 6 347

13.2.2 Anionic Polymerization of Polyamide 6 348

13.3 Review of Reactive Extrusion of Polyamide 6 in Twin-Screw Extruders 352

13.4 Recent Developments in Reactive Extrusion of Polyamide 6 in Twin-Screw Extruders 354

13.4.1 Reaction System and Experimental Setup 354

13.4.2 Influence of Number of Degassing Steps and Activator Content on Residual Monomer Content and Molecular Weight 356

13.4.3 Influence of Amount and Type of Entrainer on Residual Monomer Content and Molecular Weight 365

13.4.4 Influence of Polymer Throughput on Residual Monomer Content 367

13.5 Conclusion 368

References 369

14 Industrial Production and Use of Grafted Polyolefins 375
Inno Rapthel, Jochen Wilms, and Frederik Piestert

14.1 Grafted Polymers 375

14.2 Industrial Synthesis of Grafted Polymers 376

14.2.1 Melt Grafting Technology 377

14.2.2 Solid State Grafting Technology 378

14.3 Main Applications 380

14.3.1 Use as Coupling Agents 380

14.3.2 Grafted Polyolefins for Polymer Blending 392

14.3.2.1 Reactive Blending of Polyamides 392

14.3.3 Grafted TPEs for Overmolding Applications 400

14.4 Conclusion and Outlook 403

References 404

Index 407