Blend phase morphology

Blending offers an interesting means of tailoring product properties to specific applications. However, in the case of immiscible polymer pairs, the desired properties are not achieved readily without a compatibilizer, which enhances the phase dispersion and stability, as well as a good adhesion between the phases. This can be effectuated by physical or reactive methods [Folkes and Hope, 1993]. Compatibilization strongly affects the blend phase morphology and as such, it also may influence the crystallization behavior of the blend [Flaris et al., 1993]. Because both factors are related to the final properties of the blend, it is worth paying attention to these phenomena. 

Fra Francis, B., Thomas, S., Thomas, S. P., Ramaswamy, R., Rao, V. L. Diglycidyl ether of bisphe-nol-A epoxy resin-polyether sulfone/polyether sulfone ether ketone blends phase morphology, fracture toughness and thermo-mechanical properties. Colloid Polym. Sci. 285 (2006) 83-93. 

Sax Saxena, A., Francis, B., Rao, V. L., Ninan, K. N. Epoxy-tert-butyl poly (cyanoarylene ether) blends Phase morphology, firacture toughness, and mechanical properties. J. Appl. Polym. Sci. 100 (2006) 3536-3544. 

General Ideas and Stability of Blend Phase Morphology... 

Figure 6.8 Wu s correlation of blend phase morphology using K/ar]r and 1//17.

An important part of the present chapter discusses the interrelation between reactive compatibilization and the blend phase morphology generation, as well as the crystallization behavior of reactively compatibilized blends containing crystallizable components. The phase morphology development in reactive blending is discussed in conjunction with the non-reactive blending approach. 

The characterization of the interfacial chemical reactions and the reaction kinetics are very challenging topics in this area. In fact the quantitative analysis of the interfacial chemical reactions and reaction kinetics has still to be performed for most of the melt reactions despite their crucial importance for the understanding of the relationship between melt reactions, blend phase morphology and ultimate properties. The copolymer generated as a result of the interfacial reactions is difficult to separate and to characterize. Several investigations are still being made to identify and characterize the in situ formed copolymer. 

For a judicious control of the macroscopic properties of polymer blends, phase morphology constitutes a key parameter for many specific applications. The blending process of immiscible polymers in the melt state results in a heterogeneous morphology that is characterized by the shape, the size, and the distribution of the component phases. Depending on the composition, the homopolymer characteristics and the processing conditions used to mix them, two main types of morphologies are obtained, a dispersed type (a particle can be of any shape rod, platelet, flacks, disc, sphere, etc.) or a co-continuous one. 

Thomas S, Groeninckx G. Nylon 6 ethylene propylene rubber (EPM) blends Phase morphology development during processing and comparison with literature data. J Appl Polym Sci 1999 71 1405. 

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