Stabilization of Polymeric Materials

Plastics are used worldwide in everyday life, e.g. as food packaging, electronics, construction, automotive parts, and household appliances. To produce these products with the desired service lifetimes the use of suitable stabilizers is necessary. This book provides a concise and comprehensive overview of the basic mechanisms of plastic degradation processes caused by heat and light. At its core is a detailed description of the stabilization of different polymers, including an explanation of stabilization mechanisms and the influence of commonly used additives such as fillers, flame retardents and pigments on the stability of plastic. Every polymer scientist, material technologist, or application engineer dealing with the design of the properties of plastics will benefit from this new overview.

Contenu

1 Principles of Oxidative Degradation.- 1.1 Introduction.- 1.2 Autoxidation.- 1.3 Diffusion and Solubility of Oxygen in Polymers.- 1.4 Degradation of Polymers During Processing in the Melt.- 1.4.1 Polypropylene.- 1.4.2 Polyethylene.- 1.4.3 Polystyrene.- 1.4.4 Polyamides and Polyesters.- 1.4.5 Polyacetals.- 1.4.6 Polycarbonate.- 1.4.7 Polyurethanes.- 1.4.8 High Performance Engineering Thermoplastics.- 1.4.9 Polymer Blends and Alloys.- 1.5 Upper Limit of Processing Temperature.- 1.6 Degradation of Polymers Under Long Term Thermal Conditions.- 1.7 Degradation of Polymers by Photooxidation.- 1.7.1 Absorption of Light by Polymers.- 1.7.2 Photochemistry of Hydroperoxides.- 1.7.3 Photo-Induced Reactions.- 1.7.4 Photo Degradation of Individual Substrates.- 1.7.4.1 Polyolefins.- 1.7.4.2 Polystyrene.- 1.7.4.3 Polyester.- 1.7.4.4 Polyamides.- 1.7.4.5 Polyacetal.- 1.7.4.6 Polycarbonate.- 1.7.4.7 Polyurethanes.- 1.7.4.8 High Performance Engineering Thermoplastics.- 1.7.4.9 Polymer Blends and Alloys.- 1.7.5 Oxidation Profile of a Sample's Cross-Section.- 2 Principles of Stabilization.- 2.1 Stabilization Against Thermo-Oxidative Degradation.- 2.1.1 Inhibition of Autoxidation.- 2.1.2 H-Donors and Radical Scavengers.- 2.1.2.1 Phenolic Antioxidants.- 2.1.2.2 Aromatic Amines.- 2.1.2.3 Sterically Hindered Amines.- 2.1.2.4 Hydroxylamines.- 2.1.2.5 C-Radical Scavengers.- 2.1.3 Hydroperoxide Decomposers.- 2.1.3.1 Phosphites and Phosphonites.- 2.1.3.2 Organosulphur Compounds.- 2.1.4 Bifunctional Stabilizers.- 2.1.5 Blends of Stabilizers with Differing Functions.- 2.2 Stabilization Against Photooxidative Degradation.- 2.2.1 UV Absorbers.- 2.2.2 Quenchers.- 2.2.3 H-Donors and Radical Scavengers.- 2.2.3.1 Phenolic Antioxidants.- 2.2.3.2 Sterically Hindered Amines.- 2.2.3.3 Hydroxylamines.- 2.2.3.4 C-Radical Scavengers.- 2.2.4 Hydroperoxide Decomposers.- 2.2.5 Bifunctional Stabilizers.- 2.2.6 Blends of Stabilizers with Differing Functional Mechanisms.- Conclusions.- 3 Principles of Stabilization of Individual Substrates.- 3.1 Polyolefins.- 3.1.1 Melt Stability of Polyolefins.- 3.1.2 Long Term Thermal Stability of Polyolefins.- 3.1.3 Color Development in Polyolefins.- 3.1.4 Light Stability of Polyolefins.- 3.2 Thermoplastic Polyolefins (TPO).- 3.3 Elastomers.- 3.4 Styrenic Polymers.- 3.4.1 Polystyrene.- 3.4.2 Impact-Modified Polystyrene.- 3.4.3 Styrene/Acrylonitrile Copolymers.- 3.4.4 Acrylonitrile/Butadiene/Styrene Copolymers.- 3.5 Polyesters.- 3.6 Polyamides.- 3.7 Polyacetals.- 3.8 Polycarbonates.- 3.9 Polyurethane.- 3.10 High Performance Engineering Thermoplastics.- 3.11 Polymer Blends and Alloys.- 4 Influence of Metals, Fillers and Pigments on Stability.- 4.1 Metal Ion Deactivators.- 4.2 Fillers.- 4.3 Pigments.- 4.3.1 Non Colored Pigments.- 4.3.2 Color Pigments.- 5 Solubility and Diffusion of Stabilizers in Polymers.- 5.1 Solubility in Theory.- 5.2 Solubility in Practice.- Conclusions.- 5.3 Physical Loss of Stabilizers from Polymers Through Diffusion and Evaporation.- 5.3.1 Stabilizer Loss in Theory.- 5.3.1.1 Loss of Stabilizer by Evaporation.- 5.3.1.2 Loss of Stabilizer by Surface Precipitation.- 5.3.2 Diffusion in Practice.- Conclusions.- 5.3.3 Stabilizer Loss in Practice.- Conclusions.- 5.4 Service Lifetime Predictions for Polymer End Use Applications.- 5.4.1 Theoretical Considerations.- 5.4.2 Failure Criterion.- 6 Testing of Stabilizers in the Substrate.- 6.1 Introduction.- 6.2 Testing of Melt Stability.- 6.3 Testing of Long Term Thermal Stability.- 6.3.1 Oven Aging Techniques.- 6.3.2 Testing Under External Stress.- 6.3.3 High Pressure Oxygen Techniques.- 6.3.4 Oxygen Absorption Techniques.- 6.3.5 Chemiluminescence Techniques.- 6.4 Testing Light Stability of Polymers.- 6.4.1 Natural vs Artificial Weathering.- 6.4.2 Test Methods.- 6.5 Effect of Gamma Radiation on Polymers.- Conclusions.- 7 Outlook and Trends.- 7.1 New Substrates.- 7.1.1 Metallocene-Based Polymers.- 7.1.2 Engineering Thermoplastics.- 7.1.3 Polymer Blends and Alloys.- 7.2 Recycling of Polymers.- References.- Appendix 1.- List of Abbreviations and Symbols.- Chemical Symbols.- Physical Symbols.- Appendix 2.- Appendix 3.