scholarly journals Polymethacrylamide—An underrated and easily accessible upper critical solution temperature polymer: Green synthesis via photoiniferter reversible addition–fragmentation chain transfer polymerization and analysis of solution behavior in water/ethanol mixtures

2020 ◽  
Vol 58 (21) ◽  
pp. 3050-3060 ◽  
Author(s):  
Tilman Eckert ◽  
Volker Abetz
Keyword(s):  
Green Synthesis ◽  
Chain Transfer ◽  
Solution Temperature ◽  
Solution Behavior ◽  
Critical Solution Temperature ◽  
Reversible Addition ◽  
Upper Critical Solution Temperature ◽  
Chain Transfer Polymerization

scholarly journals Upper Critical Solution Temperature (UCST) Behavior of Polystyrene-Based Polyampholytes in Aqueous Solution

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 265 ◽  
Author(s):  
Komol Kanta Sharker ◽  
Yuki Ohara ◽  
Yusuke Shigeta ◽  
Shinji Ozoe ◽  
Shin-ichi Yusa
Keyword(s):  
Pure Water ◽  
Polymer Concentration ◽  
Degree Of Polymerization ◽  
Solution Temperature ◽  
Sulfonate Group ◽  
Trimethylammonium Chloride ◽  
Critical Solution Temperature ◽  
Reversible Addition ◽  
Upper Critical Solution Temperature ◽  
Quaternary Ammonium Group

Strong polyampholytes comprising cationic vinylbenzyl trimethylammonium chloride (VBTAC) bearing a pendant quaternary ammonium group and anionic sodium p-styrenesulfonate (NaSS) bearing a pendant sulfonate group were prepared via reversible addition-fragmentation chain-transfer polymerization. The resultant polymers are labelled P(VBTAC/NaSS)n, where n indicates the degree of polymerization (n = 20 or 97). The percentage VBTAC content in P(VBTAC/NaSS)n is always about 50 mol%, as revealed by 1H NMR measurements, meaning that P(VBTAC/NaSS)n is a close to stoichiometrically charge-neutralized polymer. Although P(VBTAC/NaSS)n cannot dissolve in pure water at room temperature, the addition of NaCl or heating solubilizes the polymers. Furthermore, P(VBTAC/NaSS)n exhibits upper critical solution temperature (UCST) behavior in aqueous NaCl solutions. The UCST is shifted to higher temperatures by increasing the polymer concentration and molecular weight, and by decreasing the NaCl concentration. The UCST behavior was measured ranging the polymer concentrations from 0.5 to 5.0 g/L.

scholarly journals Thermoresponsive and Redox Behaviors of Poly(N-isopropylacrylamide)-Based Block Copolymers Having TEMPO Groups as Their Side Chains

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Toru Uemukai ◽  
Tomoya Hioki ◽  
Manabu Ishifune
Keyword(s):  
Block Copolymers ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Solution Temperature ◽  
Thermoresponsive Polymer ◽  
Critical Solution Temperature ◽  
Redox Active ◽  
Reversible Addition ◽  
Polymerization Conditions ◽  
Active Block

Thermoresponsive and redox-active block copolymers having 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) moieties have been synthesized by using the reversible addition-fragmentation chain transfer (RAFT) polymerization technique.N-Isopropylacrylamide (NIPAAm) and 2,2,6,6-tetramethylpiperidyl methacrylate (TEMPMA) monomers were copolymerized stepwise under RAFT polymerization conditions to afford the thermoresponsive block copolymers, PNIPAAm-block-PTEMPMA and PNIPAAm-block-PTEMPMA-block-PNIPAAm. Oxidation of tetramethylpiperidine groups in the copolymers successfully afforded the corresponding TEMPO-containing block copolymers. The resulting triblock copolymer was found to be thermoresponsive showing lower critical solution temperature (LCST) at 34∘C in its aqueous solution. Redox behavior of the resulting copolymer was observed by cyclic voltammetry. The potential of anodic current peak changed below and above the LCST of the block copolymer. These results indicate that the phase transition of thermoresponsive polymer influences the redox potential of TEMPO moieties.

Hyperbranched Polymers via RAFT Copolymerization of an Acryloyl Trithiocarbonate

2007 ◽  
Vol 60 (6) ◽  
pp. 396 ◽  
Author(s):  
Andrew P. Vogt ◽  
Sudershan R. Gondi ◽  
Brent S. Sumerlin
Keyword(s):  
Click Chemistry ◽  
Lower Critical Solution Temperature ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Chain Transfer Agent ◽  
Solution Temperature ◽  
Dipolar Cycloaddition ◽  
Critical Solution Temperature ◽  
Reversible Addition ◽  
End Groups

Hyperbranched copolymers of N-isopropylacrylamide (NIPAM) and styrene were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of a novel acryloyl trithiocarbonate, namely 1-[3-(2-methyl-2-dodecylsulfanylthiocarbonylsulfanylpropionyloxy)propyl]-1H-[1,2,3]triazol-4-ylmethyl acrylate. By employing an example of ‘click chemistry’, we were able to prepare the vinyl RAFT chain transfer agent (CTA) by copper-catalyzed 1,3-dipolar cycloaddition of an azido-functionalized trithiocarbonate and propargyl acrylate. The resulting CTA facilitated the preparation of highly branched poly(N-isopropylacrylamide) (PNIPAM) and polystyrene. Interestingly, the branched PNIPAM demonstrated a reduced lower critical solution temperature (LCST) of 25°C as opposed to the conventional value of 32°C expected for linear PNIPAM, an effect attributed to increased contribution of hydrophobic dodecyl trithiocarbonate end groups.

Selective Hydrogen Bonding Controls Temperature Response of Layer-by-Layer Upper Critical Solution Temperature Micellar Assemblies

Soft Matter ◽  
2021 ◽  
Author(s):  
Aliaksei Aliakseyeu ◽  
Victoria Albright ◽  
Danielle Yarbrough ◽  
Samantha Hernandez ◽  
Qing Zhou ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Methacrylic Acid ◽  
Temperature Response ◽  
Solution Temperature ◽  
Layer By Layer ◽  
Critical Solution Temperature ◽  
Hydrogen Bonding Interactions ◽  
Upper Critical Solution Temperature ◽  
Lbl Films

This work establishes a correlation between the selectivity of hydrogen-bonding interactions and the functionality of micelle-containing layer-by-layer (LbL) assemblies. Specifically, we explore LbL films formed by assembly of poly(methacrylic acid)...

scholarly journals Synthesis of aminated polystyrene and its self-assembly with nanoparticles at oil/water interface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 317-327
Author(s):  
Chenliang Shi ◽  
Ling Lin ◽  
Yukun Yang ◽  
Wenjia Luo ◽  
Maoqing Deng ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Self Assembly ◽  
Carbon Dots ◽  
Chain Transfer ◽  
Functionalized Polymers ◽  
Amino Groups ◽  
One Dimensional ◽  
Reversible Addition ◽  
Oil Water ◽  
Chain Transfer Polymerization

AbstractThe influence of density of amino groups, nanoparticles dimension and pH on the interaction between end-functionalized polymers and nanoparticles was extensively investigated in this study. PS–NH2 and H2N–PS–NH2 were prepared using reversible addition–fragmentation chain transfer polymerization and atom transfer radical polymerization. Zero-dimensional carbon dots with sulfonate groups, one-dimensional cellulose nanocrystals with sulfate groups and two-dimensional graphene with sulfonate groups in the aqueous phase were added into the toluene phase containing the aminated PS. The results indicate that aminated PS exhibited the strongest interfacial activity after compounding with sulfonated nanoparticles at a pH of 3. PS ended with two amino groups performed better in reducing the water/toluene interfacial tension than PS ended with only one amino group. The dimension of sulfonated nanoparticles also contributed significantly to the reduction in the water/toluene interfacial tension. The minimal interfacial tension was 4.49 mN/m after compounding PS–NH2 with sulfonated zero-dimensional carbon dots.

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