Polystyrene phase diagram

We will focus on one experimental study here. Monovoukas and Cast studied polystyrene particles witli a = 61 nm in potassium chloride solutions [86]. They obtained a very good agreement between tlieir observations and tire predicted Yukawa phase diagram (see figure C2.6.9). In order to make tire comparison tliey rescaled the particle charges according to Alexander et al [43] (see also [82]). At high electrolyte concentrations, tire particle interactions tend to hard-sphere behaviour (see section C2.6.4) and tire phase transition shifts to volume fractions around 0.5 [88]. 

Khandpur A.K., Eoerster S., Bates E.S., Hamley I.W., Ryan A.J., Bras W., Almdal K., and Mortensen K. Polyisoprene-polystyrene diblock copolymer phase diagram near the order-disorder transition. Macromolecules, 28, 8796, 1995. 

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 a system of significant interest to the present works, Graillard, et al. [62] studied the ternary phase diagrams of the systems polybutadiene-styrene-polystyrene and polybutadiene-block-polystrene-styrene-polystyrene. They showed that the presence of block copolymer increased the miscibility of the two poljrmers, as the styrene component polymerized. Similar effects are probable in the IPN s, as compared with the corresponding blends. 

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])...

Fig. 1 Phase diagram of self-assembled structures in AB diblock copolymer melt, predicted by self-consistent mean field theory [31] and confirmed experimentally [33]. The MesoDyn simulations [34, 35] demonstrate morphologies that are predicted theoretically and observed experimentally in thin films of cylinder-forming block copolymers under surface fields or thickness constraints dis disordered phase with no distinct morphology, C perpendicular-oriented and Cy parallel-oriented cylinders, L lamella, PS polystyrene, PL hexagonally perforated lamella phase. Dots with related labels within the areal of the cylinder phase indicate the bulk parameters of the model AB and ABA block copolymers discussed in this work (Table 1). Reprinted from [36], with permission. Copyright 2008 American Chemical Society...

Mutually compatible polymers are relatively rare [84,85], A typical phase diagram of two incompatible polymers and a common solvent is that determined by Kern for the polystyrene - poly(p - chlorostyrene) - benzene system shown in the Fig. 1.11 [86],... 

Fig, 8. Example of phase diagram concen-tration/temperature. Copolymer polystyrene-polybutadiene SB. 31 containing 20% poly butadiene and exhibiting a Hexagonal structure. 

Fig. 9. Example of phase diagram concentration/temperature. Copolymer polystyrene-poly bu tadiene SB. 11 containing 39% polybutadiene and exhibiting a lamellar structure.

Fig. 2. Phase diagram at 340 K, showing the particle concentration p/p0 in the coexisting ordered and disordered phases as a function of the volume fraction of the free polymer for different molecular weights of the free polymer. (I), 36,000 (II), 82,000 (III), 122,000 (IV), 176,000 (V), 490,000. System polyisobutene-stabilized silica particles with polystyrene as the free polymer in cyclohexane, a = 48 nm, 6=5 lim. The lower curves represent the transition boundary from a stable disordered phase to the two-phase region, and the upper curves the two-phase region to the stable ordered phase boundary. x, = 0.47 and xs = 0.10 for polyisobutene—cyclohexane, A/kT = 4.54 and v = 0.10. The value of x for polystyrene—cyclohexane is calculated according to Eqn (16).

The phase relationships of two-phase polymer systems also have been of considerable interest in recent years. In an important series of papers, Molau and co-workers (19-24) studied systems, which were denoted POO emulsions (polymeric oil-in-oil), prepared by dissolving a given polymer in monomer and then polymerizing the monomer. During polymerizations of this type the composition of the respective phases reverses, and a phase inversion process was proposed to explain this. A similar process has been suggested as the mechanism by which poly-butadiene forms the dispersed phase in the manufacture of high-impact polystyrenes (22,25). Recently, Kruse has pointed out that this phase-inversion point may correspond to that point on a ternary phase diagram at which the reaction line bisects a tie line (26), and we have advanced a similar point of view in our earlier reports (17,18, 27). 

In the previous section we have described the three types of phase behavior observed in the low-molecular-weight PMMA/PS system and reviewed the four types observed in the low-molecular-weight PS/PMMA system. These various phase relationships have been studied in terms of their dependence on the molecular weight (Mn) and weight percent (W) of the initial polymer present. Further, we have presented quantitative data concerning the sizes of the dispersed particles, again correlated to variations in Mn and W. In this section we will discuss the results in terms of the poly (methyl methacrylate )/polystyrene/styrene and poly-styrene/poly( methyl methacrylate)/methyl methacrylate ternary phase diagrams, whichever is appropriate. 

Figure 19. Ternary phase diagram for the polystyrene/ polybutadiene/benzene system. (After Dobry and Boyer-Kawenoki (2).)...

Figure 20. Assumed ternary phase diagram for the poly(methyl methacrylate)/polystyrene/styrene system for two molecular weights of poly(methyl methacrylate)...

Khandpur AK, Forster S et al (1995) Polyisoprene-polystyrene diblock copolymer phase diagram near the order-disorder transition. Macromolecules 28 8796-8806... 

Gervais M, Gallot B (1973) Phase diagram and structural study of polystyrene - poly(ethylene oxide) block copolymers. 1. Systems polystyrene/poly(ethylene oxide)/diethyl phthalate. Makromol Chem 171 157-178... 

Tong, Z. Einaga, Y. Miyashita, H. Fujita, H., "Phase Equilibrium in Polymer + Polymer + Solvent Ternary Systems. II. Phase Diagram of Polystyrene + Polyisoprene + Cyclohexane," Macromolecules, 20, 1888 (1987). 

FIGURE 11-26 Experimental phase diagram of polystyrene of different molecular weights in acetone [redrawn from the data of Siow, Delmas and Patterson. Macromolecules, 5,29 (1972)1. 

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... 

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. 

Figure 3.4 Ternary phase diagram for the system styrene-polystyrene-polybutadiene rubber. Reproduced with permission from Encyclopedia of Polymer Science and Engineering, Mark (Ed.), John Wiley Sons, NY. Copyright John Wiley Sons...

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