Table of Content | 6 |
Introduction | 10 |
1 Educational Minimum: Manufacture, Structure, and Mechanical Properties of Polyethylene Resins | 14 |
1.1 Classification and Applications of Polyethylene Resins | 14 |
1.2 Catalysts for Synthesis of Polyethylene Resins | 17 |
1.3 Industrial Processes for the Manufacture of Polyethylene Resins | 19 |
1.4 Chemistry of Ethylene Polymerization Reactions | 21 |
1.5 Molecular Weight Distribution of Polymers and Methods of its Analysis | 24 |
1.6 Examples of Molecular Weight Distribution of Polyethylene Resins | 27 |
1.7 Copolymer Statistics and its Application to Description of LLDPE and VLDPE Resins | 33 |
1.8 Compositional Uniformity of Commercial Polyethylene Resins | 35 |
1.9 Morphology of Polyethylene Resins | 39 |
1.10 Mechanical Deformation of Polyethylene Resins | 42 |
References | 44 |
2 Melt Index and Melt Flow Ratio of Polyethylene Resin | 48 |
2.1 Introduction | 48 |
2.2 Basics of Polymer Rheology | Melt Flow Through a Capillary50 |
2.2.1 Flow of Polymer Melt Through a Cylindrical Capillary | 52 |
2.2.2 Melt Index of Newtonian Liquid | 53 |
2.3 Melt Flow of Monodisperse Polyethylene Resins | 54 |
2.4 Additivity Rules for Viscosity | Calculation of Melt Indexes and Melt Flow Ratios from Molecular Weight Distribution Data56 |
2.4.1 Additivity Rules for Zero-Shear Viscosity .0 | 56 |
2.4.2 Additivity Rules for Effective Viscosity and General Expressions for Flow of Non-Newtonian Multi-Component Melt | 57 |
2.5 Examples of Melt Flow Rates and Melt Flow Ratios for Polyethylene Resins of Different Types | 61 |
2.5.1 LLDPE Resins Produced with Supported Ziegler-Natta Catalysts | 61 |
2.5.2 HDPE Resins with Broad Molecular Weight Distributions | 64 |
2.5.3 Effect of Long-Chain Branching | 66 |
References | 67 |
3 Melting Point of Polyethylene Resin | 70 |
3.1 Introduction | 70 |
3.2 Melting Point of HDPE Resin | 71 |
3.3 DSC Melting Curves and Melting Points of LLDPE and VLDPE Resins Produced with Single-Site Catalysts | 74 |
3.3.1 Crystallization Process of Compositionally Uniform Ethylene/a-Olefin Copolymers | 77 |
3.3.2 Model for Secondary Crystallization | 78 |
3.3.3 Combined DSC Model for LLDPE and VLDPE Resins | 79 |
3.4 DSC Melting Curves and Melting Points of LLDPE Resins Produced with Multi-Site Ziegler-Natta Catalysts | 81 |
References | 84 |
4 Crystallinity Degree and Density of Polyethylene Resins | 86 |
4.1 Crystallinity Degree | 86 |
4.1.1 Measurement Methods | 86 |
4.1.2 Definition of Crystallinity Degree of LLDPE and VLDPE Resins Based on Copolymer Statistics | 88 |
4.2 Density | 89 |
4.2.1 Measurement Methods | 90 |
4.2.2 Physical Meaning of Polyethylene Density | 90 |
References | 93 |
5 End-Use Mechanical Properties of Polyethylene Film | 96 |
5.1 Mechanical Properties of Polyethylene Resins | 96 |
5.1.1 Effect of Testing Speed on Mechanical Properties | 97 |
5.1.2Orientation in Polyethylene Film | 98 |
5.2 Dart Impact Strength of LLDPE Film | 100 |
5.2.1 Description of Dart Impact Test | 100 |
5.2.2 Model of Dart Impact Test | 102 |
5.2.2.1 Effects of Mechanical Properties of Resins | 105 |
5.2.2.2 Comparison of Film Made from Ethylene/Butene and Ethylene/Hexene Copolymers | 106 |
5.2.2.3 Effect of Copolymer Composition | 107 |
5.2.2.4 Compositionally Uniform and Compositionally Nonuniform Resins | 108 |
5.3 Tear Strength of LLDPE and LDPE Film | 110 |
5.3.1 Description of Tear Test | 110 |
5.3.2Physical Details of Tear Test | 110 |
5.3.3Model of Tear Test | 115 |
5.3.3.1 Effect of Pendulum Speed | 120 |
5.3.3.2 Effects of Mechanical Properties of Resins | 120 |
5.3.3.3 Effect of Film Orientation | 121 |
5.3.3.4 Comparison of Tear Strength of Ethylene/Butene and Ethylene/Hexene Copolymers | 123 |
5.3.3.5Low Density Polyethylene | 123 |
5.4 Comparison of Factors Determining Results of Tear Test and Dart Impact Test of LLDPE Film | 124 |
References | 125 |
6 End-Use Testing of High Molecular Weight HDPE and MDPE Resins | 128 |
6.1 Top Load Test of HDPE Containers | 128 |
6.1.1 Mechanics of Top Load Test | 129 |
6.2 Dynamic Burst Test of HDPE Tubing and Pipes | 131 |
6.3 Static Burst Test and Long-Term Fatigue in Polyethylene | 132 |
6.3.1 Principal Equation for Low-Stress Failure | 133 |
6.3.2 Physical Mechanism of Polymer Failure under Low Stress | 135 |
6.4 Environmental Stress-Cracking Resistance | 138 |
6.4.1 Description of ESCR Test | 138 |
6.4.2 Physics of Environmental Stress Cracking | 139 |
6.4.3 Structural Parameters of HDPE Resins Affecting ESCR | 140 |
6.4.4 Relationship between ESCR and Long-Term Fatigue in Polyethylene | 143 |
6.4.5 Mechanism of Environmental Stress Cracking | 145 |
References | 148 |
Index | 152 |