Poly equilibrium phase diagrams

Low molecular weight PS and poly(methyl phenyl sUoxane), PMPS, was used — the neat resins showed Newtonian behavior. The equilibrium phase diagram was determined by optical means. Within the miscible region, blends viscosity followed the log-additivity rule, provided that the concentration was corrected for difference in the surfaces [Mertsch and Wolf, 1994] ... 

PER Pereira, M., Wu, Y.T., Madeira, P., Venando, A., Macedo, E., and Teixeira, J., Liquid-hquid equilibrium phase diagrams of new aqueous two-phase systems Ucon 50-HB5100 + ammonium sulfate + water, Ucon 50-HB5100 + poly(vinyl alcohol) + water, Ucon 50-HB5100 + hydroxypropyl starch + water, and poly(ethylene glycol) 8000 + poly(vinyl alcohol) + water, J. Chem. Eng. Data 49,43,2004. 

State instead of equilibrium one. As a result, the equilibrium phase diagram with two individual poly sulfides is modified to that witli one nonstoichiometric phase, see fig, 3. Therefore, the method of automatically monitoring the weight change with low sensitivity is not suitable for studying phase equilibria in polysulfides systems. 

Figure 7.22 represents a typical DSC ttace of copolymer melting. The poly(ethylene-co-vinyl acetate) is expected to follow a eutectic phase diagram. The melting temperature decreases from the value of the homopolymer, but the crystallinity decreases much more than expected from the small amount of noncrystallizable comonomer. Also, the crystallization of a eutectic component, required by an equilibrium phase diagram, seen for example in Fig. 7.1, is rarely observed in random copolymers with short repeating units, as in vinyl polymers. 

BOU Bouchaour, T., Benmouna, F., Roussel, F., Buisine, J.-M., Coqueret, X., Benmouna, M., and Maschke, U., Equilibrium phase diagram of poly(2-phenoxyethyl acrylate) and 5CB, Polymer, 42, 1663, 2001. 

In summary, the above studies provide the equilibrium phase diagram of the Ci2MG-water system below 80°C. This work established, in addition, that the cloud point boundary is absent below 100 °C. (This is the boundary of the liquid/liquid miscibility gap commonly found in the diagrams of nonionic surfactant water systems). The absence of the cloud point boundary is significant with respect to analysis of the intrinsic hydrophilicity of this poly functional group [2]. The kinetic and nonequilibrium aspects of the phase behavior of aqueous C12MG mixtures will now be considered. 

In 2005, Tyler et al. were the first to predict the existence of the orthorhombic Fddd as an equilibrium structure in the phase diagram of diblock copolymers. Using self-consistent field theory, the calculated phase diagram is shown in Fig. 4.3a [13, 16]. Two years later, Takenaka et al. were the first to deliver the experimental proof for the existence of the Fddd microdomain structure, discovered in a PS-ft-PI diblock copolymer melt [17], Thereafter, Kim et al. determined the Fddd phase boundaries in PS- -PI melts, as illustrated in Fig.4.3b [14, 18]. Although it was believed that the latest phase diagram of diblock copolymer was complete. Ho et al. in 2009 reported the discovery of a helical cylinder phase in poly(styrene)-f>-poly (L-lactic acid) melts, see Fig.4.3c [15]. 

Figure 7.30 illustrates the limits from equilibrium to cold crystallization. They are based on a computer calculation for three-dimensional cold crystallization. It is assumed in this case that sequences of less than three A-units do not crystallize, and that at least two out of the four neighboring chains must match the sequence of three repeating units to make the central sequence crystalline. If all four lateral neighbors are crystalline, the repeating unit is in the interior of the crystal, if only three are crystalline, it is on the surface, and if only two are crystalline, it is part of an edge. With this critical sequence length and two surface free energies, experimental data of poly(ethylene terephthalate-co-sebacate) can be discussed, as is shown in Fig. 7.31. The experimental phase diagram of the same copolymer, but after slower cooling, is displayed in Fig. 7.26.

A weakly segregated rod-coil block copolymer system composed of poly(2,5-diethylhexyloxy-l,4-phenylene-vinylene) (DEH-PPV) rod blocks and PI coil blocks was used to map the equilibrium phase behavior with respect to temperature, molecular weight, and coil ffaction. The phase diagram is shown in Figure 17. These results show lamellar and hexagonal nanostructured phases and both nematic and isotropic phases where the rods and coils are miscible. 

ZAF Zafarani-Moatlar, M.T., Hamzehzadeh, S., and Hosseinzadeh, S., Phase diagrams for liquid-hquid equilibrium of ternary poly(ethylene glycol) + disodium tartrate aqueous system and vapor-liquid equilibrium of constituting binary aqueous systerrrs at r = (298.15, 308.15, and 318.15) K. Experiment and correlation. Fluid Phase Equil, 268, 142, 2008. 

Fig. 16. (a) Phase diagram of poly(ethylene oxide) 3,500/100,000 mol-wt mixtures at different concentrations. The open circles represent the calculation of and, calculated by using the Flory-Huggins equations 46 and 47, respectively. The filled symbols represent the experimental data, (b) Phase diagram of polyethylene dissolved in 1,2,4,5-tetrachlorobenzene (TCB). The experimental data were obtained by melting after crystallization. The macromolecular crystals, 2, were not at equilibrium, but melted considerably lower than (see Table 1). 

Frequently encountered in nature and process industries, multiphase flows may comprise various states of matter, e.g., gas and solid in fluidization gas and liquid in bubble column and gas, liquid, and solid in airlift slurry bed (Mudde, 2005). In this article, the term phase in multiphase flow is related to the aggregative state of flow, which is normally far from equilibrium states. And it is different from the phase for a thermodynamic equilibrium system, where the phase is used to refer to a set of equilibrium states that can be demarcated in terms of state variables by a phase boundary on a phase diagram. As a result, it is possible to have a gas—soHd flow mixture with more than two phases, which can be classified by size, density of particles, or by the states of dispersion, e.g., poly disperse multiphase flow pCue and Fox, 2014) and dilute—dense, gas—soHd multiphase flow (Hong et al, 2012). 

The purpose of the ternary diagram is to enable us to quickly read the eomposition at equilibrium at a certain temperature and a certain pressure, knowing the initial conditions, for reactions involving a single phase with three components (mixture of three gases or eondensed solution with components). As the reaction may also involve pure phases - e g. solids -we shall write it very generally with its three eomponents in the poly component phase A], A2 and A3, in the form ... 

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