Poly blend phase diagram

Fig. 14 Creation of a single specimen polymer blend phase diagram from orthogonal polymer composition and temperature gradients. The polymers are polystyrene and poly(vinyl methyl ether) (PVME) a composition library placed orthogonal to a temperature gradient b completed gradient library polymer blend phase diagram. White points are data derived from traditional measurement for comparison. See text for details, (b reproduced with permission from [3])...

Avella, M., Martuscelli, E. Poly-d(-)(3-hydroxybutyrate)/poly(ethylene oxide) blends phase diagram, thermal and crystallization behavior. Polymer 29(10), 1731-1737 (1988)... 

Blends of poly(vinyl chloride) (PVC) and a-methylstyrene—acrylonitrile copolymers (a-MSAN) exhibit a miscibiUty window that stems from an LCST-type phase diagram. Figure 3 shows how the phase-separation temperature of 50% PVC blends varies with the AN content of the copolymer (96). This behavior can be described by an appropriate equation-of-state theory and interaction energy of the form given by equation 9. 

Figure 10.7 The phase diagram (a) and the glass transition temperatures (b) of a PSC/PVME mixture obtained, respectively, by light scattering and differential scanning calorimetry (DSC). Irradiation experiments were performed in the miscible region at 127 C indicated by (X) in the figure of trans-cinnamic acid-labeled polystyrene/poly(vinyl methyl ether) blends.

In the case of polystyrene blends with poly(vinyl methyl ether) two phase behaviour was found for blends from various chlorinated solvents whereas single phase behaviour was found for blends from toluene The phase separation of mixtures of these polymers in various solvents has been studied and the interaction parameters of the two polymers with the solvents measured by inverse gas chromatography It was found that those solvents which induced phase separation were those for which a large difference existed between the two separate polymer-solvent interaction parameters. This has been called the A% effect (where A% = X 2 Xi 3)-A two phase region exists within the polymer/polymer/solvent three component phase diagram as shown in Fig. 2. When a dilute solution at composition A is evaporated, phase separation takes place at B and when the system leaves the two phase region, at overall... 

In situ polymerisation does not however guarantee homogeneous blends as two phase regions can exist within the polymer/polymer/monomer three component phase diagram. In the case of vinyl chloride polymerisation with solution chlorinated polyethylene, the vinyl chloride has limited solubility in both poly(vinyl chloride) and chlorinated polyethylene. The phase diagram has the form shown in Fig. 3 The limit of swelling of vinyl chloride in the chlorinated polyethylene is A and the highest concentration of PVC prepared by a one-shot polymerisation is B. 

Miscible blends of poly(vinyl methyl ether) and polystyrene exhibit phase separation at temperatures above 100 C as a result of a lower critical solution temperature and have a well defined phase diagram ( ). This system has become a model blend for studying thermodynamics of mixing, and phase separation kinetics and resultant morphologies obtained by nucleation and growth and spinodal decomposition mechanisms. As a result of its accessible lower critical solution temperature, the PVME/PS system was selected to examine the effects of phase separation and morphology on the damping behavior of the blends and IPNs. 

Blends of polystyrene/poly(2,6-dimethyl-l,4-phenylene oxide) and polystyrene/poly(vinyl methyl ether) were investigated by IGC over wide composition and temperature ranges. Flory-Huggins free energy parameters were obtained and are discussed as the criterion for thermodynamic miscibility. From the temperature variation of the free energy parameter, phase diagrams for both blends were obtained. 

Phase diagrams of polymer blends and solutions (open symbols are binodals and filled symbols are spinodals). (a) Polymer blends of poly(vlnyl methyl ether) (A/ = 51 500 g mol ) and various molar masses of polystyrene (circles have Af = 10 000 g mol, squares have M = 20400 g moP, hexagons have M=5l 000 g mol , diamonds have A/ = 200000 g moP ), data from T. K. Kwei and T. T. Wang, in Polymer Blends, Vol. 1 (D. R. Paul and S. Newman, editors). Academic Press, 1978. (b) Polyisoprene solutions in dioxane------... 

The effect of dissolved CO2 on the miscibility of polymer blends and on phase transitions of block copolymers has been measured with spectroscopy and scattering (40). The shifts in phase diagrams with CO2 pressure can be pronounced. Polymer blends may be trapped kinetically in metastable states before they have time to phase separate. Metastable polymer blends of polycarbonate (PC) and poly(styrene-cn-acrylonitiile) were formed with liquid and supercritical fluid CO2 in the PCA process, without the need for a surfactant. Because of the rapid mass transfer between the CO2 phase and the solution phase, the blends were trapped in a metastable state before they... 

Sophiea et al. published the first classical composition-temperature phase diagram, working with the semi-IPN net-polyurethane-mter-poly(vinyl chloride) [Sophiea et al., 1994b]. They found a lower critical solution temperature, LCST = 120°C below this temperature the system was one-phased, and above, two-phased. Such behavior is now known to be characteristic of most polymer blends (see Chapter 2). 

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] ... 

Morphological Phase Diagrams of Blends of Polypropylene Isomers with Poly(Ethylene-Octene) Copolymer... 

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