Reactive Extrusion

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.

Auteur
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).

Contenu

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 ofThermoplastic 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 andModeling 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 KinematicModeling of Distributive Mixing 88

4.4.2 Numerical Simulation 89

4.4.3 Experimental Validation 92

4.4.4 DistributiveMixing Performance and Efficiency 93

4.5 Summary 97

References 98

5 In-processMeasurements 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*</...