Lower critical solution Macromolecule

Siow, K.S. Delmas, G. Patterson, D., "Cloud-Point Curves in Polymer Solutions with Adjacent Upper and Lower Critical Solution Temperatures," Macromolecules, 5, 29 (1972). 

Barbalata, A. Bohossian, T. Prochazka, K. Delmas, G., "Characterization of the Molecular Weight Distribution of High- Density Polyethylene by a New Method Using Turbidity at a Lower Critical Solution Temperature," Macromolecules, 21, 3186 (1988). 

Cowie, J. M. G. Maconnachie, A. Ranson, R. J., "Phase Equilibria in Cellulose Acetate-Acetone Solutions. The Effect of the Degree of Substitution and Molecular Weight on Upper and Lower Critical Solution Temperatures," Macromolecules, 4, 57 (1971). 

Konno, S. Saeki, N. Kuwahara, N. Nakata, M. Kaneko, M., "Upper and Lower Critical Solution Temperatures in Polystyrene Solutions. IV. Role of Configurational Heat Capacity," Macromolecules, 8, 799 (1975). 

Kubota, K. Abbey, K. M. Chu, B., "Static and Dynamical Properties of a Polymer Solution with Upper and Lower Critical Solution Points. NBS 705 Polystyrene in Methyl Acetate," Macromolecules, 16, 137 (1983). 

Kataoka K, Miyazaki H, Okano T, and Sakurai Y. Sensitive glucose-induced change of the lower critical solution temperature of poly[N, N-dimethylacrylamide-co-3-acrylamido[phenylhoronic acid] in physiological saline. Macromolecules 1994 27 1061-1062. 

Cowie, J. M. G., and I. J. McEwen. 1974. Polymer-cosolvent systems. IV Upper and lower critical solution temperatures in the systems methylcyclohexane-diethyl ether-polystyrene. Macromolecules. 7 291-296. 

Saeki, S., N. Kuwahara, S. Konno, and M. Kaneko. 1973. Upper and lower critical solution temperatures in polystyrene solutions. Macromolecules 4 246-250. 

Slow, K. S., G. Delmas, and D. Patterson. 1972. Cloud-fwint curves in polymer solutions with adjacent upper and lower critical solution temperatures. Macromolecules. 5 29-34. 

Both PNIPAAm and PVME exhibit unique thermo-shrinking properties. Thus, as an aqueous solution is heated beyond a certain point, the polymer shrinks and a phase separation occurs. This temperature is commonly referred to as the lower critical solution temperature (LCST). For PNIPAAm, it lies between ca. 30 and 35°C, the exact temperature being a function of the detailed microstructure of the macromolecule. Below LCST, the polymer is soluble in the aqueous phase, as the chains are extended and surrounded by water molecules. Above the LCST, the polymer becomes insoluble and phase separation occurs. Because of the abrupt nature of these transitions and their reversibility (which allows repeated thermal switching) these polymers have stirred up particular interest in the field of science and engineering since their first appearance in the open literature in 1956. 

Kapnistos, M., Hinrichs, A., Vlassopoulos, D., Anastasiadis, S. H., Stammer, A., and Wolf, B. A., Rheology of a lower critical solution temperature binary polymer blend in the homogeneous, phase-separated, and transitional regimes. Macromolecules, 29, 7155-7163 (1996). 

SA2 Saeki, S., Kuwahara, N., and Kaneko, M., Pressirre dependence of upper and lower critical solution temperamres in polystyrene scAvAiom, Macromolecules, 9, 101, 1976. 

Feil, H. et al, 1993. Effect of comonomer hydrophilicity and ionization on the lower critical solution temperature of A-isopropylacrylamide copolymers. Macromolecules, 26(10), 2496-2500. 

Moelbert, S. De Los Rios, P. 2003, Hydrophobic interaction model for upper and lower critical solution temperatures . Macromolecules, vol. 36, no. 15, pp. 5845-5853. 

Ougizawa, T., Inoue, T. Kammer, H.W. 1985, Upper and lower critical solution temperature behavior in polymer blends . Macromolecules, vol. 18, pp. 2092-2094. 

Figure 21 (a) Calculated reactivity ratios for DMAEMA and PEGMA monomers in RAF polymerization, (b) Dependence of lower critical solution temperature (LOST) on PEGMA polymer composition and pH. (c) Calculated surface energies of copolymer thin films. Adapted from Fournier, D. Hoogenboom, R. Thijs, H. M. L. etal. Macromolecules 2007, 40(4), 915-920, and reprinted with permission from the American Chemical Society. 

The solubility of macromolecules as a rule improves with the rising temperature. Solvent - polymer mixtures usually exhibit the upper consolute temperature or upper critical solution temperature, UCST, with a maximum on the plot of system concentration versus temperature. Above the critical solution temperature, polymer is fully soluble at any concentration. For practical work, the systems with UCST below ambient temperature are welcome. There are, however numerous polymer - solvent systems, in which the solvent quality decreases with increasing temperature. The plot of system concentration versus temperature exhibits a minimum. The phenomenon is called lower consolute temperature or lower critical solution temperature, LCST Polymer is only partially soluble or even insoluble above lower critical solution temperature. This unexpected behavior can be explained by the dominating effect of entropy in case of the stiff polymer chains or by the strong solvent - solvent interactions. The possible adverse effect of rising temperature on polymer solubility must be kept in mind when woiking with low solubility polymers and with multicomponent mobile phases. It may lead to the unforeseen results especially in the polymer HPLC techniques that combine exclusion and interaction retention mechanisms, in coupled methods of polymer HPLC (see section 11.8, Coupled Methods of Polymer HPLC). 

MO1 Mori, H., Kato, I., Saito, S., and Endo, T., Proline-based block copolymers displaying upper and lower critical solution temperatures, Macromolecules, 43, 1289, 2010. 

SHE Shechter, L, Ramon, O., Portnaya, L, Paz, Y., and Livney, Y.D., Microcalorimetric study of the effects of a chaotropic salt, KSCN, on the lower critical solution temperature (LCST) of aqueous poly(Y-isopropylacrylamide) (PNIPA) solutions, Macromolecules, 43, 480, 2010. 

Horst, R. and Wolf, B.A. (1991) Calculation of shear influences on the phase separation behavior of polymer solutions in the region of flieir lower critical solution temperature. Creation of closed miscibility gaps. Macromolecules, 24 (9), 2236-2239. 

Lee, S. B. Song, S. C. Jin, J. I. Sohn, Y. S. A new class of biodegradable thermosensitive polymers. 2. Hydrolytic properties and salt effect on the lower critical solution temperature of poly(organophosphazenes) with methoxypoly(ethylene glycol) and amino acid esters as side groups. Macromolecules 1999, 32, 7820-7827. 

Madbouly Wolf, 2002, Equilibrium phase behavior of polyethylene oxide and of its mixtures with tetrahydronaphthalene or/and p ly (ethylene oxide-block-dimethylsiloxane), /, Chem. Phys., Vol. 117, No. 15, PP. 7357-7363 Maderek et al. 1983, High-temperature demixing of poly(decyl methacrylate) solutions in isooctane and its pressure-dependence, Makromol. Chem., Vol. 184, No. 6, PP. 1303-1309 Lower critical solution temperatures of poly(decyl methacrylate) in hydrocarbons, Eur. Polym.., Vol. 19, No. 10, PP. 963-965 Patterson Robard, 1978, Thermodynamics of polymer compatibility. Macromolecules, Vol. 11, No. 4, 690-695... 

Rabeony et al 1998, Effect of pressure on polymer blend miscibility A temperature-pressure superposition. Macromolecules, Vol. 31, No. 19, PP. 6511-6514 Rodgers, 1991, Procedure for predicting lower critical solution temperature behavior in binary blends of polymers. Macromolecules, Vol. 24, No. 14, PP. 4101-4109 Rudolf Cantow, 1995, Description of phase-behavior of polymer blends by different equation-of-state theories. 2. excess volumes and influence of pressure on miscibility. Macromolecules, Vol. 28, No. 19, PP. 6595-6599... 

COW Cowie, J.M.G., Macoimachie, A., and Ranson, R.J., Phase equilibria of cellulose acetate-acetone solutions. The effect of degree of substitution and molecular weight on upper and lower critical solution temperature. Macromolecules, 4, 57, 1971. 

BAR Baibalata, A., Bohossian, T., Prochazka, K., and Delmas, G., Characterization of the molecular weight distribution of high-density polyethylene by a new method using the turbidity at a lower critical solution temperature, Macromolecules, 21. 3286, 1988. 

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