Polymer Blends and Alloys

P. S. HOPE and M. J. FOLKES Mixing two or more polymers together to produce blends or alloys is a well-established strategy for achieving a specified portfolio of physical proper ties, without the need to synthesise specialised polymer systems. The subject is vast and has been the focus of much work, both theoretical and experimental. Much ofthe earlier work in this field was necessarily empirical and many ofthe blends produced were of academic rather than commercial interest. The manner in which two (or more) polymers are compounded together is of vital importance in controlling the properties of blends. Moreover, particular ly through detailed rheological studies, it is becoming apparent that process ing can provide a wide range of blend microstructures. In an extreme, this is exemplified by the in situ formation of fibres resulting from the imposition of predetermined flow fields on blends, when in the solution or melt state. The microstructures produced in this case transform the blend into a true fibre composite; this parallels earlier work on the deformation of metal alloys. This type of processing-structure-property correlation opens up many new possi bilities for innovative applications; for example, the production of stiff fibre composites and blends having anisotropic transport properties, such as novel membranes. This book serves a dual purpose.

Klappentext
This book provides an authoritative and up-to-date survey of the technology available to synthesize and test polymer blends and alloys, and of the future applications which developments in processing are offering. Emphasis is on the properties required by industry, and how these properties can be achieved and tested.

Zusammenfassung
FOLKES Mixing two or more polymers together to produce blends or alloys is a well-established strategy for achieving a specified portfolio of physical proper ties, without the need to synthesise specialised polymer systems.

Inhalt
1 Introduction.- 2 Practical aspects of processing blends.- 2.1 Introduction.- 2.2 Mechanisms of dispersion.- 2.3 Construction and operating principle of compounders.- 2.4 Comparative testing.- References.- 3 Compatibilisation and reactive blending.- 3.1 Introduction.- 3.2 Compatibilisation mechanisms.- 3.3 Methods of compatibilisation.- 3.4 Systems using compatibiliser addition.- 3.5 Systems using reactive blending.- 3.6 Future trends.- References.- 4 Rheology of polymer blends.- 4.1 Introduction.- 4.2 Experimental measuring data obtained in simple flow fields.- 4.3 Miscibility and flow behaviour of polymer blends.- 4.4 Flow behaviour of immiscible polymer blends.- 4.5 Drop break-up in two-phase flow: Newtonian drop in Newtonian medium.- 4.6 The role of coalescence.- 4.7 Non-steady-state flow (transition to steady state).- 4.8 Complex flow: processing of polymer blends.- Nomenclature.- References.- 5 Practical techniques for studying blend microstructure.- 5.1 Light microscopy.- 5.2 Scanning electron microscopy.- 5.3 Transmission electron microscopy.- 5.4 Thermal analysis.- 5.5 Other techniques.- 5.6 Conclusions.- References.- 6 Theoretical aspects of polymer blends and alloys.- 6.1 Introduction.- 6.2 General consideration of the properties of polymer blends and alloys.- 6.3 Simple formulae for the mechanical properties of blends and their limitations.- 6.4 Exact formulae derived for ideal materials.- 6.5 Special relations for particular geometries.- 6.6 Orientation.- 6.7 Temperature dependence of mechanical properties.- References.- Further reading.- 7 Toughened polymers.- 7.1 Introduction.- 7.2 Toughened thermoplastics.- 7.3 Toughened thermosets.- 7.4 Toughening mechanisms.- 7.5 Particle size distributions.- 7.6 Influence of processing on toughness of modified polymers.- 7.7 Conclusion.- References.- 8 Blends containing liquid crystal polymers.- 8.1 Introduction.- 8.2 The effect of LCPs on the processing of polymers.- 8.3 Reinforcement using LCPs.- 8.4 Other possible applications of LCP blends.- 8.5 Future applications.- References.- 9 Fibre forming and in situ fibre composites.- 9.1 Introduction.- 9.2 In situ composites: a review.- 9.3 In situ fibre production in extruded blends.- 9.4 Ram extrusion of S-B-S/HDPE blends.- 9.5 Uniaxial drawing of polymer blends.- 9.6 Conclusions and further aspects of in situ fibre forming technology.- References.