Morphology of immiscible polymer

The effect of viscosity ratio on the morphology of immiscible polymer blends has been studied by several researchers. Studies with blends of LCPs and thermoplastics have shown indications that for good fibrillation to be achieved the viscosity of the dispersed LCP phase should be lower than that of the matrix [22,38-44]. 

Since the processing conditions and mixing equipment have a crucial effect on the morphology of immiscible polymer blends [45], experiments were carried out in four different types of extruders to find optimal conditions for blend preparation and fibrillation. Nevertheless, the morphologies of PP-LCP blends produced by... 

B. D. Favis, Factors Influencing the Morphology of Immiscible Polymer Blends in melt Processing, in Polymer Blends, Vol. I, D. R. Paul and C. B. Bucknall, Eds., Wiley-Interscience, New York, 1999. 

Meijer et al. [1988] and Elemans et al. [1988] investigated the potential of electron irradiation to stabilize the morphology of immiscible polymer blends. Their concept was that selective crosslinking of a dispersed phase in a matrix that remains unaffected, or degrades, should help fix the morphology of the blend. 

The morphology of immiscible polymer systems is largely dictated by the value of interfacial tension, composition, and the values of viscosity of the component polymers. 

Chaotic mixing flows have recently been used for rapid development of morphology of immiscible polymers. Three morphological forms have been identifled -lamella, flbrils, and droplets (Figure 8.12) [200-205]. 

FIGURE 1.5 Variation of the first normal stress difference versus strain for (O) uncompati-bilized blends of polydimethylsiloxane (PDMS) in polyisoprene (PI) and for ( ) 10% com-patibilized blends of polydimethylsiloxane (PDMS) with polyisoprene (PI). (Adapted from Van Hemelrijck Ellen. Effect of physical compatibilization on the morphology of immiscible polymer blends. PhD thesis, K U Leuven, 2005.)... 

Van Hemelrijck Ellen. Effect of physical compatibilization on the morphology of immiscible polymer blends. PhD thesis, K U Leuven, 2005. 

It is well known that the mechanical properties of polymer blends are determined by their composition, domain size, and domain size distribution. The ability to monitor and control the morphology of immiscible polymer blends is very important. For example, Epstein and Carhart [56] used a Newtonian model for emulsions and derived relationships for the attenuation as a function of blend composition, domain size, R, and frequency,/ A longitudinal wave propagating in the matrix approaching an interface with a domain of the second fluid will give rise to reflected, transmitted shear and thermal waves, while excess attenuation can be determined as a linear function of the composition. A similar approach was also described elsewhere [57]. 

Effect of Flow Geometty on the Steady-State Shear Viscosity and Morphology of Immiscible Polymer Blends... 

Different monomers may be copolymerized to modify the properties of thermoplastics. For the same purpose, homo- and copolymers are frequently mixed with other substances, including other polymers, various fillers, and nanofillers. The presence of comonomers in macromolecules, as well as interactions between macromolecules in miscible blends, can affect both crystallization and morphology of the polymeric material. Interfaces and the confinement of polymer chains within a finite volume influence the solidification and morphology of immiscible polymer blends and polymer-based composites. They are also of special importance in ultra-thin polymer layers where the thickness is comparable to or smaller than the lamellar crystal thickness itself... 

INFLUENCE OF STAGGERING ANGLE OF KNEADING BLOCK ON PHASE MORPHOLOGY OF IMMISCIBLE POLYMER BLENDS IN... 

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