scholarly journals Influence of cyclodextrin on the UCST- and LCST-behavior of poly(2-methacrylamido-caprolactam)-co-(N,N-dimethylacrylamide)

2014 ◽  
Vol 10 ◽  
pp. 1951-1958 ◽  
Author(s):  
Alexander Burkhart ◽  
Helmut Ritter
Keyword(s):  
Free Radical ◽  
Nmr Spectroscopy ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Radical Mechanism ◽  
Methacryloyl Chloride ◽  
Critical Solution Temperature ◽  
Free Radical Mechanism ◽  
Upper Critical Solution Temperature ◽  
Lcst Behavior

The monomer 2-methacrylamido-caprolactam (4) was synthesized from methacryloyl chloride (3) and racemic α-amino-ε-caprolactam (2). Copolymerization of 4 with N,N-dimethylacrylamide (5) was carried out by a free-radical mechanism using 2,2’-azobis(2-methylpropionitrile) (AIBN) as an initiator. The new copolymers show a lower critical solution temperature (LCST) in water and an upper critical solution temperature (UCST) in ethanol, 1-propanol, and 1-butanol. The solubility properties of the copolymers can be influenced significantly by the addition of randomly methylated β-cyclodextrin (CD). The complexation of the copolymers with CD, was confirmed by the use of ROESY-NMR-spectroscopy.

Polymer Fractionation at a Lower Critical Solution Temperature Phase Boundary

1967 ◽  
Vol 40 (5) ◽  
pp. 1544-1552
Author(s):  
C. H. Baker ◽  
C. S. Clemson ◽  
G. Allen
Keyword(s):  
Molecular Weight ◽  
Phase Boundary ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Two Samples ◽  
Polymer Fractionation ◽  
Molecular Weight Fractions

Abstract The influence of pressure on a lower critical solution temperature is much more pronounced than on an upper critical solution temperature. Accordingly it is possible to control phase separation at a LCST phase boundary under isothermal conditions by merely adjusting the pressure on the system. An apparatus has been constructed to investigate the isothermal fractionation of polyisobutene in which precipitation is controlled by pressure. Two samples of polyisobutene of Mv=1.76×106 and 9.0×104 have been fractionated in isopentane solution so as to yield up to six and nine fractions respectively. The integral molecular weight distribution curves thus obtained are compared with those obtained from conventional fractionations at an UCST. The sensitivity of the method is poor with regard to the separation of low molecular weight fractions and degradation occurs at the higher temperatures to an appreciable extent.

Substituent Effects on a Photo-Induced Alternation of the Lower Critical Solution Temperatures of Poly(N-isopropylacrylamide) with Azobenzene Units

2001 ◽  
Vol 710 ◽  
Author(s):  
Haruhisa Akiyama ◽  
Nobuyuki Tamaoki
Keyword(s):  
Free Radical ◽  
Visible Light ◽  
Lower Critical Solution Temperature ◽  
Water Solubility ◽  
Substituent Effects ◽  
Ultra Violet ◽  
Wettability Alteration ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Soluble Polymers

ABSTRACTWe synthesized copolymers of N-isopropylacrylamide (NIPAM) and azobenzene-containing acrylates or acrylamides by free radical polymerization, and investigated the water solubility of these polymers upon irradiation with ultra-violet and visible light. The solubility depended on concentration and structure of photoreactive azobenzene unit in the polymers. The soluble polymers showed the lower critical solution temperature, which was varied along with light irradiation. Photo-induced large wettability alteration was observed in the film.

Zwitterionic poly(sulfobetaine methacrylate)s in water: from upper critical solution temperature (UCST) to lower critical solution temperature (LCST) with increasing length of one alkyl substituent on the nitrogen atom

2018 ◽  
Vol 9 (43) ◽  
pp. 5257-5261 ◽  
Author(s):  
Ning Wang ◽  
Bryan T. Seymour ◽  
Evan M. Lewoczko ◽  
Ethan W. Kent ◽  
Ming-Li Chen ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Lower Critical Solution Temperature ◽  
Alkyl Substituent ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Alkyl Length

Increasing the alkyl length on nitrogen of the polymer changes behaviour from UCST, to soluble, LCST, and insoluble.

scholarly journals Oligomeric epoxide–amine adducts based on 2-amino-N-isopropylacetamide and α-amino-ε-caprolactam: Solubility in presence of cyclodextrin and curing properties

2013 ◽  
Vol 9 ◽  
pp. 2803-2811 ◽  
Author(s):  
Julian Fischer ◽  
Helmut Ritter
Keyword(s):  
Differential Scanning Calorimetry ◽  
Lower Critical Solution Temperature ◽  
Setting Time ◽  
Diglycidyl Ether ◽  
Solution Temperature ◽  
Scanning Calorimetry ◽  
Critical Solution Temperature ◽  
Lcst Behavior ◽  
Oscillatory Rheology ◽  
Amine Adducts

2-Amino-N-isopropylacetamide and α-amino-ε-caprolactam were reacted with glycerol diglycidyl ether to give novel oligomeric thermoresponsive epoxide–amine adducts. These oligomers exhibit a lower critical solution temperature (LCST) behavior in water. The solubility properties were influenced with randomly methylated β-cyclodextrin (RAMEB-CD) and the curing properties of the amine–epoxide mixtures were analyzed by oscillatory rheology and differential scanning calorimetry, whereby significant differences in setting time, viscosity, and stiffness were observed.

scholarly journals Designing the thermal behaviour of aqueous biphasic systems composed of ammonium-based zwitterions

2017 ◽  
Vol 19 (17) ◽  
pp. 4012-4016 ◽  
Author(s):  
Ana M. Ferreira ◽  
Helena Passos ◽  
Akiyoshi Okafuji ◽  
Mara G. Freire ◽  
João A. P. Coutinho ◽  
...  
Keyword(s):  
Thermal Behaviour ◽  
Lower Critical Solution Temperature ◽  
Water Soluble ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Aqueous Biphasic Systems ◽  
Upper Critical Solution Temperature ◽  
Aqueous Biphasic ◽  
Biphasic Systems

The design of the thermal behaviour – from an upper critical solution temperature (UCST) to a lower critical solution temperature (LCST) – of aqueous biphasic systems composed of water-soluble ammonium-based zwitterions.

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