Low Density Cellular Plastics -

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Résumé :
1 Physical behaviour of polymeric foams - an overview.- 1.1 General.- 1.2 Foam formation.- 1.3 Cell structure.- 1.4 Matrix polymer morphology.- 1.5 Thermal behaviour.- 1.6 Stress-strain behaviour.- 1.7 Energy management.- 1.8 Final comments.- References.- 2 Polyurethane flexible foam formation.- 2.1 Introduction.- 2.2 Reaction chemistry.- 2.3 Morphology development.- 2.4 The cell opening mechanism.- 2.5 Conclusions.- Acknowledgements.- References.- 3 Characterizations of polymeric cellular structures.- 3.1 Introduction.- 3.2 Background.- 3.3 Quantitative characterization.- 3.4 Stereology.- 3.5 Difficulties associated with measurement.- 3.6 Optical microscopy.- 3.7 Final comments.- Acknowledgements.- References.- 4 The morphology of flexible polyurethane matrix polymers.- 4.1 Introduction.- 4.2 The dynamics of phase separation.- 4.3 The morphological characterization of foams.- 4.4 Summary.- Acknowledgements.- References.- 5 Heat transfer in foams.- 5.1 Introduction.- 5.2 Conduction heat transfer.- 5.3 Radiative heat transfer.- 5.4 Gas conduction.- 5.5 Overall conductivity.- Acknowledgements.- Appendix A: Lower limit analysis.- Appendix B: List of symbols.- References.- 6 Thermal ageing.- 6.1 Introduction.- 6.2 Theory and modelling.- 6.3 Experimental methods.- 6.4 Different testing methods.- Appendix: List of symbols.- References.- 7 The elastic behavior of low-density cellular plastics.- 7.1 Introduction.- 7.2 Elastic behavior of perfectly ordered two-dimensional foams.- 7.3 Elastic behavior of three-dimensional foams.- 7.4 Future directions.- Acknowledgements.- References.- 8 Hysteresis and energy loss in flexible polyurethane foams.- 8.1 Introduction.- 8.2 Mechanical response.- 8.3 Definitions and relationships.- 8.4 Mechanisms.- 8.5 Static hysteresis.- 8.6Dynamics hysteresis.- 8.7 Ball rebound resilience.- 8.8 Conclusions.- Appendix: List of symbols.- References.- 9 Impact response.- 9.1 Introduction.- 9.2 Macroscopic deformation geometry.- 9.3 Cell geometry and deformation mechanisms.- 9.4 Impact properties.- 9.5 Relation of impact properties to microstructure.- 9.6 Packaging design.- 9.7 Complex impacts.- 9.8 Discussion.- References.- 10 Acoustic characteristics of low density foams.- 10.1 Introduction.- 10.2 Single-wave approximation for foams with a low flow resistivity.- 10.3 Acoustic properties of foams of medium and high flow resistivity.- 10.4 Matrix representation of layered porous materials.- 10.5 Conclusion.- Appendix A: Matrix elements.- References....

Biographie:
2. closeto idealenergymanagement - hencetheir useinthermalandacoustic insulation, vibration damping, acoustic absorption and shock mitigation...

Sommaire:
Foams are gas filled integral structures in which the gas is finely dispersed throughout acontinuouslyconnected solid phase. The bulk density is usually substantially lower than that of the solid component, and for the foams which form the focus for this book the volume fraction of the gas phase is considerably greater than 0.5 and in most instances in excess of 0.9. Many ofthe materials encountered in every day experience, such as bread, plants and trees, structural materials for buildings, comfort materials for domestic and automotive seating, shock absorbers or car bumpers and materials for noise control, have one thing in common - the cellular nature of their physical structure. Whyare thesestructuressoimportantin the naturaland man-made world? The reasons are both technical and commercial. From a technical viewpoint cellular materials offer: 1. high specific stiffness and strength - making them suitable for structural applications...