Dispersed phase domains

Els and McGill [48] reported the action of maleic anhydride on polypropylene-polyisoprene blends. A graft copolymer was found in situ through the modifier, which later enhanced the overall performance of the blend. Scott and Macosko [49] studied the reactive and nonreactive compatibilization of nylon-ethylene-propylene rubber blends. The nonreactive polyamide-ethylene propylene blends showed poor interfacial adhesion between the phases. The reactive polyamide-ethylene propylene-maleic anhydride modified blends showed excellent adhesion and much smaller dispersed phase domain size. 

It is the intent of this doeument to define the terms most commonly encountered in the field of polymer blends and eomposites. The scope has been limited to mixtures in which the eomponents differ in ehemical composition or molar mass or both and in which the continuous phase is polymeric. Many of the materials described by the term multiphase are two-phase systems that may show a multitude of finely dispersed phase domains. Hence, incidental thermodynamic descriptions are mainly limited to binary mixtures, although they can be and, in the scientific literature, have been generalized to multicomponent mixtures. Crystalline polymers and liquid-crystal polymers have been considered in other documents [1,2] and are not discussed here. 

Process by which an initially continuous phase domain becomes the dispersed phase domain and the initially dispersed phase domain becomes the continuous phase domains... 

Multiphase morphology in which dispersed phase domains of one polymer contain and completely encapsulate many phase domains of a second polymer that may have the same composition as the continuous phase domain. 

Polymer composite consisting of a polymer continuous phase and disperse phase domains of microscopic ceramic particles. 

The large circles represent a dispersed phase (bubbles, droplets, or solids), while the small ones represent surface modified nanoparticles (SMNs) dispersed in the continuous phase that can be found between dispersed phase domains. The diagram on the left illustrates that the SMNs must be dispersed in the continuous phase. If they are not well dispersed or are agglomerated, they will not work as efficiently. 

SEBS-g-MA (0-20) and dispersed phase domain size vs. volume fraction 1995 Rosch and... 

Data, collected by random experimental runs using probability and statistical models, may be a good way of approaching the responses of the system inside the experimental space scanned (19). Then, this would be a preliminary consideration when undertaking a model for a disperse phase/continuous matrix systems where the dispersed phase domains are rigid. 

Large shear rates enhance deformation capabilities of the dispersed phase domains generally as droplets, flowing with the matrix during the mixing and further... 

With moderate compatibility, intermediate and complex phase behavior results. Thus IPNs with dispersed phase domains have been reported ranging from a few micrometers (the largest) to a few hundred nanometers (intermediate) to those without a resolvable domain structure (complete mixing). With highly incompatible polymers, on the other hand, the thermodynamics of phase separation is so powerful that it occurs before it can be prevented by cross-linking. 

The above theories are based on a polymer composite where the matrix and the dispersed phase are well defined, i.e., the matrix and the dispersed phase are both single components of the system. The properties of the matrix material are dominant in determining the composite properties. Theoretically, the equations will represent the composite properties better if the volume fraction of the dispersed phase is small, since they implicitly assume no Interaction between the dispersed phase domains. 

The determination of T of a blend is one of the calorimetric techniques used to elucidate the miscibility or partial miscibility in the amorphous phase of binary polymer blends. Glass transition temperature is the temperature at which the transition from the glassy to the rubbery state of the bulk material takes place. The establishment of miscibility using is based on the degree of dispersion of the second component in the amorphous region of the first component and that the size of the disperse phase domain is < 15 nm (Silvestre et al., 1996 Shultz and Young, 1980). It is noteworthy that blends which exhibit a are miscible whereas... 

PA-6 (30-25) or PA-12/PP (60-70)/PP-MA (0-20) Internal mixer at 240 °C/TEM/mechanical properties and dispersed phase domain size vs. vol. fraction of compatibilizer/also blends containing EP rubber Rosch et al. 1996 Rosch 1995 Rosch and Miilhaupt 1993, 1995a, b... 

The presence of clay particles at the interface in a blend can occur when the interfacial energies are appropriate, and this will result in improved interfacial adhesion between the two polymer phases and a decrease in the dispersed phase domain size. The final morphology in the blend is also affected by the viscosity ratio of the dispersed and continuous phases and has been known to significantly... 

A mixing process in which the dispersed phase domains are uniformly distributed - a reduction of nonuniformity. 

The study of the physical form and structure of a material. The overall physical form of the physical structure of a material on a submicron and micron scale. Common units are dispersed phase domains, lamellae, spherulites, etc. The term comprises notion of the global structure (e.g., stress-induced skin core), as well as shape, size, orientation, and distribution of the dispersed phase (solid, liquid, or gaseous). 

Initial morphologies of extruded strands were examined as a function of extruder rpm and blend composition. Phase contrast optical microscopy shows a 35% HDPE dispersed phase domain size to be comparable (1 p. < size < 5 p) at both 300 and 500 rpm, (Fig. 5.9). The effect of compatibilizer on domain size of the dispersed phase is shown in Fig. 5.10. 

Definition of terms related to polymer blends, composites, and multiphase polymeric materials This recommendation defines the most commonly used terms encountered when dealing with polymer blends and composites and is limited to mixtures in which the components differ in chemical composition or molar mass or both and in which the polymer forms the continuous phase. Many of the multiphase systems are in fact biphasic systems with a multitude of finely dispersed phase domains. Crystalline and liquid crystalline multiphase systems are the subject of other documents. 

Many of the studies of multiphase polymers are conducted on unsaturated rubbers which are adequately stained by osmium tetroxide, which reveals the nature of the dispersed phase domains. Polymers with activated aromatic groups have been selectively stained by reaction with mercuric trifluoroacetate (Section 4.4.8). Hobbs [262] has successfully used this technique to provide contrast in blends of poIy(2,6-dimethyl-l,4-phenylene oxide) and Kraton G (SBS block copolymer). Although this stain is effective in enhancing contrast, a drawback of the method is that the material is not hardened or fixed by the stain. 

Fig. 5.73 Carbon black particles (arrows) are shown in a sectioned carbon black filled polymer (A) to be aggregates of smaller particles less than 0.1 iim in diameter. Interestingly, a black, multiphase pol)nner, shown in a TEM micrograph of an ultrathin section (B), has carbon black particles within the dispersed phase domains.

Many of the studies of multiphase polymers are conducted on unsaturated rubbers which are adequately stained by osmium tetroxide, which reveals the nature of the dispersed phase domains. 

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