Blend three-phase

Asari T, Matsuo S, Takano A, Matsushita Y. Three-phase hierarchical structures from AB/CD diblock copolymer blends with complemental hydrogen bonding interaction. Macromolecules 2005 38 8811-8815. 

The electrical conductivity of two-phase, incompatible polymer blends containing carbon black has been shown to depend on the relative affinity of the conductive particles to each of the polymer components in the blend, the concentration of carbon black in the filler-rich phase, and the structural continuity of this phase [82]. Hence, by judicious manipulation of the phase microstructure, these three-phase filled composites can exhibit double percolation behaviour. 

Fig. 638 Calculated constant %N (=11) phase diagram for a symmetric diblock blended with high-molecular-weight homopolymers (Janert and Schick 1997b). Biphasic regions are unlabelled. Note the large region of three-phase coexistence between the lamellar and the A-rich and B-rich disordered phases, (a) Both homopolymers have 0 = 1.5 (b) ft = 1.0, ft = 1.5.

Fig. 6.41 Calculated constant xN (=11.0) phase diagram for a blend containing equal amounts of two homopolymers and a symmetric diblock, all with equal chain length (Janert and Schick 1997a). The region of three-phase coexistence between ordered lamellar phases is shaded. Extrapolated phase boundaries are shown with dashes.

Surface tension plays a significant role in the deformation of polymers during flow, especially in dispersive mixing of polymer blends. Surface tension, as, between two materials appears as a result of different intermolecular interactions. In a liquid-liquid system, surface tension manifests itself as a force that tends to maintain the surface between the two materials to a minimum. Thus, the equilibrium shape of a droplet inside a matrix, which is at rest, is a sphere. When three phases touch, such as liquid, gas, and solid, we get different contact angles depending on the surface tension between the three phases. 

To examine the effect of phase separation on the loss modulus, a sample of a 50/50 chemical blend was phase separated by annealing at 130 C and then evaluated by DMS, Figure 8. Note that the unannealed 50/50 blend shows a broad transition similar to that obtained by DSC and by Hourston and Hughes (24). As compared to the unannealed blend, the annealed PVME/PS blend shows a broader transition. Similarly, the IPN has a still broader transition than the blend. However, the LA s for the three samples are relatively constant, 5%, agreeing also with theory. Table II. Note that overall experimental error is 10%. Also, it was observed that the phase separated blend has a milky white appearance whereas the IPN is slightly hazy. This indicates that the size of the phase separated domains in the IPN are smaller. 

When a block copolymer is blended with a homopolymer that differs in composition from either block the usual result is a three-phase structure. Miscibility of the various components is not necessarily desirable. Thus styrene-butadiene-styrene block copolymers are recommended for blending with high density polyethylene to produce mixtures that combine the relative high melting behavior of the polyolefin with the good low temperature properties of the elastomeric midsections of the block polymers. 

Polyimide-Based Syntactic Foam (9). Three-phase syntactic foams were made using a polyimide solution (22% PI-2080 in DMF) and hollow glass microspheres (Type B-30-B, 3M Co.) which have a particle density of 0.25 to 0.30 cm and a bulk density of 0.182 g/cm . The solution and glass spheres were hand mixed and packed into a 5" x 5" mold and compacted under pressure. Variations of foam density were obtained by molding specific quantities of blend into different volumes ranging from Vi to 1" in thickness. Greater densities required higher pressures with the maximum density obtained at a pressure of about 100 psi. 

The identification of phases in polymer blends can be accomplished in force modulation mode (FMM) AFM. Using FMM AFM the relative moduli (a convolution of storage and loss moduli) are mapped on the specimen surface. The rms amplitude of the FMM cantilever, driven in an oscillatory fashion, reflects directly the modulus of underlying polymer specimen. In the blend discussed below three phases can be differentiated. 

A related reactor is that for coal liquefaction, which can be carried out in a three-phase slurry bubble column (see Fig. 5). Hydrogen can be supplied at the bottom of a column of downcoming product—oil. The solid coal reactant is blended with the product or carrier oil and fed at the top. The generic process depicted in Fig. 5 is a generalization of the liquefaction reactor in the Exxon Donor Solvent Process. As the gas flow rate increases, the bubbles change from uniformly small to chaotic. In the H-coal process, both the gas and a coal-oil slurry are fed from the bottom in an ebullating-bed reactor. Catalyst solids are fed from the top. This reactor operates as an expanded... 

In experiments on immiscible blends, as noted by Dlubek et al. [2002], it is to be anticipated that the PALS parameters h and T3 will depend on the volume fractions and compositions of the three phases, as well as the effect of any interaction between the blend components. Such interactions have been identified in the studies of Wastlund et al. [1998] and Dlubek et al. [1999]. Thus, as pointed out above, the decrease in T3 observed by Wastlund et al. [1998] in 50 50 SMA24/SANx blends when the acrylonitrile content of the SANx increases from x=22% to x=33%, is interpreted as being due to increased interaction between the maleic anhydride and acrylonitrile groups. On the other hand, Dlubek et al. [1999] studied blends of an acrylonitrile-butadiene-styrene (ABS) copolymer and polyamide-6 (PA-6). This blend may be assumed to be quite heterogeneous, consisting of a two-phase structure having PA-6 crystals embedded in an amorphous ABS matrix and elastomeric... 

An x-ray structure analysis showed that the samples with more than 50 mol.% Cu2GeSe3 had three phases (Table 3) two had the structure of zinc blende (Cj = 5.59 kX and 03 = 5.55 kX) and one had a tetragonal lattice (Oj = 5.61 kX and C3/2 = 5.50 kX). These phases remained unchanged right up to the composition with 90 mol.% Cu2GeSe3. 

By separating the individual heat flow components TMDSC can be used to distinguish overlapping thermal events with different behaviours. Figure 2.10A shows a DSC curve of the first heat of a PET/ acrylonitrile-butadiene-styrene (ABS) blend. Three transitions associated with the PET phase are observed ... 

A very large market for such chemical as tertiary butyl alcohol may open if lead antiknock additives are reduced in gasoline blends. Alcohols (methanol, ethanol, tertiary butyl-alcohol) and ethers (methyltertbutylether) are among these components which can be used to boost octane number. Their synthesis will involve addition of water or alcohols to olefins. This can be realized in three phase systems. 

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