Poly phase separation role

Tsai, F.-J. Torkelson, J. M., "Roles of Phase Separation Mechanism and Coarsening in the Formation of Poly(methyl methacrylate) Asymmetric Membranes," Macromolecules, 23, 775 (1990). 

F.J. Tsai, J.M. Torkelson, Roles of phase separation mechanism and coarsening in the formation of poly(methyl methacrylate) asymmetric membranes. Macromolecules 23 (1990) 775. 

Chapter 6 occupicsi the most mophase separation, including Wunderlich s (1973, 1976, 1980) fundamental monographs. Nevertheless, the matter of this chapter, in its relation to th< others, must play a pphase separation in polymer systems. This chapt< r also reports th< results of application of the turbidity spectrum method to phase analysis of some systems with a crystallizing polymers poly(vinyl alcohol) -I- water and poly(ethylenc oxide) -I- water, wliosc treatment by well-established metlio[Pg.853]

The cloud point curves for unfilled poly(vinyl acetate) - poly(me-thyl methacrylate) mixtures and those filled with 10% of non-modified and silanized fumed silica show that curves for filled mixtures are situated at much lower temperature than those for unfilled material.It should be noted that the temperature of phase separation decreases sharply in the region where one alloy component has a predominant content. The addition of silane-treated fumed silica also results in a lower temperatures of phase separation. These effects were attributed to the difference in adsorption of both components at the interface with a solid and are connected with the asymmetry of interaction in the system. The phase separation temperature in this alloy also depends on the filler content (Figure 7.4). At the same time, the phase separation temperature depends on the ratio of components. This fact may be interpreted as indirect confirmation of the role of asymmetry of interactions, because increasing the filler content should affect the as5mimetry of the interactions and therefore have an... 

An excellent example of the role played by liquid-liquid phase separation in the ensuing crystallization is found in blends with syndiotactic poly(styrene).(77) Measurements of the glass temperature in mixtures with poly(2,6-dimethyl-l,4-diphenylene oxide) (PPO) indicate that the components are miscible in all proportions in the melt. However, mixtures of syndiotactic poly(styrene) with poly(vinyl methyl ether) represent partially miscible blends. When the poly(vinyl methyl ether) content exceeds 20% by weight, the melt separates into two liquid phases, one rich in syndiotactic poly(styrene), the other in poly(vinyl methyl ether). Thus, the two blends have a common crystallizing component. However, in one the crystallization takes place from a homogeneous melt in the other from one that is phase separated. The different melt structures profoundly affect the crystaflization kinetics. This can be seen when a comparison is made between the crystallization kinetics of syndiotactic poly(styrene) from a homogeneous or phase separated melt. 

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