Polymer Blends and Phase Separation

Abstract

Polymers may be created using a single monomer or more than one monomer element. A range of structures with nano-scale dimensions can be created using polymers with segments of different molecular structure—block copolymers. It is also possible to blend together certain polymer systems and observe physical properties which are different form those of the individual polymers used. This chapter considers the thermodynamic influences which control the phase characteristics of polymer blends. Incorporation of a second phase can also have advantageous effects on the mechanical properties and the toughening of polystyrene and epoxy resins will be considered in detail. Polyurethanes are able to partially phase separate and the physical properties of these materials depend critically on the extent to which phase separation is achieved during synthesis.