UCST upper critical solution

When there is a UCST (upper critical solution temperature), then above that temperature the components are fully mixable. When cooling down to below this UCST a region of segregation can be reached, in particular when the volume fractions do not differ too much (see MT Figure 9.3, lower part "upside down")... 

Figure 8.2 Schematic phase diagrams for thermoplastic-epoxy monomer (diglycidyl ether of bisphenol A) blends, (CPC = cloud point curve, and VC = vitrification curve), (a) and (b) UCST (upper critical solution temperature) behaviour for PPE and PEI (respectively) - DGEBA n = 0.15 (c) LCST (lower critical solution temperature) behaviour for PES-DGEBA y n = 0.15. (Pascault and Williams, 2000 - Copyright 2001. Reprinted by permission of John Wiley Sons Inc.)...

Figure 3 The composition-temperature diagram for pure poly-olefins showing UCST (upper critical solution temperature) and LCST (lower critical solution temperature) behaviour (because of the nature of this mixture, the UCST cannot be observed and therefore is dotted)...

LLE strongly depends on the temperature and the molecular weight. Typically, two LLE areas are observed, one at low tanperatures (UCST = upper critical solution temperature) and one at high temperatures (LCST = lower critical solution temperature). LCST is typically observed at temperatures between the boiling point and the critical temperature of the solvent. 

SAN Poly(styrene-co-acrylonitrile) UCST Upper Critical Solution... 

PB PBT polybutadiene poly(butylene terephthalate) UCST upper critical solution temperature... 

Although investigated in lesser detail earlier, the science and technology of polymer blends had its emergence in the 1970 s. Many of the basic principles existed prior to that time e.g., Flory-Huggins thermodynamic principles as well as contributions by Guggenheim and Prigogine). Commercial blends existed for decades before, however the concept of miscibility, phase behavior, and the basic nature of polymer blends was not well understood or appreciated. An initial review of polymer blends [Bohn, 1968] listed only 12 miscible polymer pairs, some of which were minor variations in copolymer structure. The review also noted that UCST (upper critical solution... 

UCST Upper Critical Solution Temperature VL Vapor-Liquid System... 

UCST Upper critical solution temperature UV Ultraviolet... 

SMA Styrene-co-maleic anhydride SPEEK Sulfonated poly(ether ether ketone) TGA Thermogravimetric analyzer TMOS Tetramethyl bisphenol A oligosulfones UCST Upper critical solution temperature... 

TEM Transmission electron microscopy ToF-SIMS Top of flight secondary ion mass spectrometry UCST Upper critical solution temperature UHMWPE Ultra high molecular weight polyethylene WAXD Wide angle X-ray diffraction XPS X-ray photoelectron spectroscopy... 

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