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.

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.

A polyelectrolyte-containing copolymer with a gas-switchable lower critical solution temperature-type phase transition

2019 ◽  
Vol 10 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Jin-Jin Li ◽  
Yin-Ning Zhou ◽  
Zheng-Hong Luo ◽  
Shiping Zhu
Keyword(s):  
Phase Transition ◽  
Cloud Point ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Type Phase

A polyelectrolyte-containing copolymer with a CO2/N2-switchable cloud point, resulting from the gas-induced alternation of hydrophilicity, was prepared.

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