Synthesis of Thermo-Responsive Fluorinated Star-Shaped Polymers by Living Cationic Polymerization

2011 ◽  
Vol 1312 ◽  
Author(s):  
Tomomi Irita ◽  
Katsuhiko Imoto ◽  
Takabumi Nagai ◽  
Sadahito Aoshima
Keyword(s):  
Aqueous Solutions ◽  
Cloud Point ◽  
Cationic Polymerization ◽  
Solution Temperature ◽  
Responsive Polymers ◽  
Molecular Weight Distributions ◽  
Living Cationic Polymerization ◽  
Bifunctional Initiators ◽  
Cloud Points ◽  
End Group

ABSTRACTWell-controlled fluorinated star-shaped polymers with oxyethylene units were designed and synthesized by living cationic polymerization. These fluorinated star-shaped polymers were prepared using successive fluorinated initiators to generate fluorinated, end-functionalized and hydrophilic segments with oxyethylene. Poly(vinyl ether)s with oxyethylene units are known to be thermo-responsive polymers that exhibit a lower critical solution temperature (LCST) in aqueous solutions. These novel fluorine-containing star-shaped polymers with oxyethylene were also thermo-responsive, as expected. In addition, the hetero-fluorinated star-shaped polymers with oxyethylene segments and different fluorine compositions were synthesized with various bifunctional initiators by living cationic polymerization having narrow molecular weight distributions (Mw/Mn=1.23−1.29) and contained very little, if any, presence of the linear homopolymer precursor, as evidenced by GPC. The LCST of this polymer depended on the end group fluorine composition and significant changes in cloud points were observed in water, as confirmed by static light scattering (SLS) measurements. As an example, aqueous solutions the star-shaped polymers without fluorine terminal groups showed no cloud point below up to 60 ºC in aqueous solution. After the fluoro-functionality was incorporated into the terminal groups, the cloud point of the aqueous solutions decreased to almost 20 ºC.

scholarly journals Effects of the Hydrophilic–Lipophilic Balance of Alternating Peptides on Self-Assembly and Thermo-Responsive Behaviors

2019 ◽  
Vol 20 (18) ◽  
pp. 4604 ◽  
Author(s):  
Ihsan ◽  
Nargis ◽  
Koyama
Keyword(s):  
Aqueous Solutions ◽  
Self Assembly ◽  
Polymer Chains ◽  
Systematic Evaluation ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Hydrophilic Lipophilic Balance ◽  
Upper Critical Solution Temperature ◽  
Cloud Points ◽  
Micellization Behavior

A series of N-substituted poly(Gly–alter–Val) peptides were successfully synthesized for the systematic evaluation of the micellization behavior of alternating peptides. Three-component polymerization employing an aldehyde, a primary ammonium chloride, and potassium isocyanoacetate afforded four alternating peptides in excellent yields. We investigated the dependence of the hydrophilic–lipophilic balance of alternating peptides on the micellization behavior. All the aqueous solutions of alternating peptides exhibited upper critical solution temperature (UCST) behaviors, strongly indicating that the alternating binary pattern would mainly contribute to the UCST behaviors. The cloud points of alternating peptides shifted to higher temperatures as the side chains became more hydrophilic, which is opposite to the trend of typical surfactants. Such unusual micellization behaviors appeared to be dependent on the quasi-stable structure of single polymer chains formed in water.

scholarly journals Naturally-Derived Amphiphilic Polystyrenes Prepared by Aqueous Controlled/Living Cationic Polymerization and Copolymerization of Vinylguaiacol with R–OH/BF3·OEt2

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1404 ◽  
Author(s):  
Hisaaki Takeshima ◽  
Kotaro Satoh ◽  
Masami Kamigaito
Keyword(s):  
Molecular Weight ◽  
Ferulic Acid ◽  
Cationic Polymerization ◽  
Living Polymerization ◽  
Block Copolymerization ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Living Cationic Polymerization ◽  
Naturally Occurring ◽  
Weight Distributions

In this study, we investigated direct-controlled/living cationic polymerization and copolymerization of 4-vinylguaiacol (4VG), i.e., 4-hydroxy-3-methoxystyrene, which can be derived from naturally-occurring ferulic acid, to develop novel bio-based amphiphilic polystyrenes with phenol functions. The controlled/living cationic polymerization of 4VG was achieved using the R–OH/BF3·OEt2 initiating system, which is effective for the controlled/living polymerization of petroleum-derived 4-vinylphenol in the presence of a large amount of water via reversible activation of terminal C–OH bond catalyzed by BF3·OEt2, to result in the polymers with controlled molecular weights and narrow molecular weight distributions. The random or block copolymerization of 4VG was also examined using p-methoxystyrene (pMOS) as a comonomer with an aqueous initiating system to tune the amphiphilic nature of the 4VG-derived phenolic polymers. The obtained polymer can be expected not only to be used as a novel styrenic bio-based polymer but also as a material with amphiphilic nature for some applications.

scholarly journals Temperature-Responsive Polymers for Biological Applications

2003 ◽  
Vol 785 ◽  
Author(s):  
M. Rackaitis ◽  
E. Manias
Keyword(s):  
Temperature Response ◽  
Water Soluble ◽  
Solution Temperature ◽  
Biological Applications ◽  
Polymer Grafting ◽  
Grafted Polymers ◽  
Water Soluble Polymers ◽  
Soluble Polymers ◽  
Responsive Polymers ◽  
Cloud Points

ABSTRACTWater soluble polymers with tunable lower critical solution temperature (LCST) are of increasing interest for biological applications such as cell patterning, smart drug release, DNA sequencing etc. The present study addresses control of the polymer temperature response in water by varying chemical composition of the monomer. In order to achieve this a series of polymers were designed and synthesized based on an ethyleneoxide/ethylene monomer (EO/EE). Polymers were synthesized using polycondensation reactions of difunctional m-EO and n-EE oligomers. The cloud point follows linearly the balance of hydrophobic/hydrophilic interaction and can be tailored in the range of 7 – 70°C by varying the m/n composition and polymer type. Polymer grafting onto the silicon surface exhibits similar solubility behaviour. Adhesion energy measurements show that grafted polymers have solubility cloud points at the temperatures that are close to the ones of the bulk polymer solutions.

Cloud Point Curves of Aqueous Solutions of Poly(N-ethylmethacrylamide)

1993 ◽  
Vol 58 (10) ◽  
pp. 2370-2382 ◽  
Author(s):  
Miloslav Bohdanecký ◽  
Jiří Horský ◽  
Vladimír Petrus ◽  
Libuše Mrkvičková ◽  
Karel Ulbrich
Keyword(s):  
Molecular Weight ◽  
Aqueous Solutions ◽  
Cloud Point ◽  
Threshold Concentration ◽  
Solution Temperature ◽  
Threshold Temperature ◽  
Critical Solution Temperature ◽  
Dilute Solution Properties ◽  
Experimental Errors ◽  
The Difference

Aqueous solutions of poly(N-ethylmethacrylamide) have a lower critical solution temperature (LCST). Cloud point curves of five polydisperse samples (Mw . 10-6 = 0.06 to 2.04) in aqueous solutions at concentrations from 0.002 to 0.1 g/ml were obtained. The threshold concentration was found to be almost independent of the molecular weight. The threshold temperature decreases moderately with increasing M and the limiting value for infinite M obtained by the Shultz-Flory method is ΘLPE = 340.5 K. This value is lower by 2.5 K than the temperature ΘLη at which the intrinsic viscosity is proportional to the square root of the molecular weight. The difference cannot be assigned to experimental errors. The entropy-of-dilution parameter is negative (ψ = -2) and much higher than the value obtained from dilute solution properties. The differences in Θ and ψ values are discussed in terms of theory of polymer solutions where a higher-order interaction parameter is included.

scholarly journals Polymer Having Dicationic Structure in Dumbbell Shape for Forward Osmosis Process

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 571 ◽  
Author(s):  
Taehyung Kim ◽  
Changha Ju ◽  
Chanhyuk Park ◽  
Hyo Kang
Keyword(s):  
Aqueous Solutions ◽  
Pure Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Solution Temperature ◽  
Solute Flux ◽  
Responsive Polymers ◽  
Draw Solution ◽  
Efficient Recovery

The thermal-responsive polymers, poly(alkane-1,#-diylbis(tri-n-butylphosphonium) 4-vinylbenzenesulfonate) (PSSBP#, # = 8, 6, and 4), where # is the number of carbon atoms in the central bridge structure of the dicationic phosphonium moiety, were synthesized to examine their potential application as draw solutes in forward osmosis (FO). The polymers exhibited low critical solution temperature (LCST) characteristics in aqueous solutions, which is essential for recovering a draw solute from pure water. The LCSTs of the 20 wt% aqueous solutions of PSSBP8, PSSBP6, and PSSBP4 were confirmed to be approximately 30, 38, and 26 °C, respectively, which is advantageous in terms of energy requirements for the recovering draw solute. When the concentration of the PSSBP4 draw solution was 20 wt%, water flux and reverse solute flux were approximately 1.61 LMH and 0.91 gMH, respectively, in the active layer facing the draw solution (AL-DS) system when the feed solution was distilled water. The PSSBP# thermal-responsive draw solute has considerable potential for use as a next-generation draw solute because of its excellent osmotic performance and efficient recovery. Therefore, this study provides inspiration for novel ideas regarding structural transformations of polymers and their applicability as draw solutes.

scholarly journals How to manipulate the upper critical solution temperature (UCST)?

2017 ◽  
Vol 8 (1) ◽  
pp. 220-232 ◽  
Author(s):  
Jukka Niskanen ◽  
Heikki Tenhu
Keyword(s):  
Aqueous Solutions ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Ph Influence ◽  
Counter Ions ◽  
Upper Critical Solution Temperature

In this mini-review, we discuss multi-stimuli-responsive polymers, which exhibit upper critical solution temperature (UCST) behavior mainly in aqueous solutions, and focus on examples where counter ions, electricity, light, or pH influence the thermoresponsiveness of these polymers.

scholarly journals Nicotine aqueous solutions: pH-measurements and salting-out effects - analysis of the effective Gibbs energies of hydration and ionic strengths of the solutions

2014 ◽  
Vol 79 (7) ◽  
pp. 829-842 ◽  
Author(s):  
Nikola Grozdanic ◽  
Marta Calado ◽  
Mirjana Kijevcanin ◽  
Slobodan Serbanovic ◽  
Zoran Visak
Keyword(s):  
Aqueous Solutions ◽  
Cloud Point ◽  
Sodium Sulfate ◽  
Potassium Nitrate ◽  
Inorganic Salts ◽  
Ph Measurements ◽  
Salting Out ◽  
Hydrogen Bond Interactions ◽  
Gibbs Energies ◽  
Cloud Points

This work is a continuation of our previous studies on the phase demixing - salting-out effects - in aqueous nicotine solutions. Thus, pH measurements were carried out allowing a brief analysis of the existing hydrogen bond interactions. Salting-out effects - the related experimental cloud point shifts - provoked by the addition of two inorganic salts, potassium nitrate and sodium sulfate, which were not studied so far, were determined. Analysis of the current and our previously reported salting-out/or salting-in phenomena in nicotine aqueous solutions was performed. In this respect, five studied salts were included: four inorganic salts (sodium chloride, potassium nitrate, sodium sulfate and sodium phosphate (Na3PO4)) and ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate ([C2mim][EtSO4] or ECOENG212?). Based on the pH measurements the effective Gibbs energies of hydration and ionic strengths of the respective ternary solutions were calculated and plotted against the related cloud-point shifts caused by the addition of the salts. For the studied salts, the results and diagram obtained within this work may be used to predict the cloud-points shifts, based on the related quantities of the salts added and/or the molar Gibbs energies of hydration and/or ionic strengths requested in each case.

Low cost bifunctional initiators for bidirectional living cationic polymerization of olefins. I. isobutylene

2017 ◽  
Vol 55 (22) ◽  
pp. 3716-3724 ◽  
Author(s):  
Turgut Nugay ◽  
Balazs L. Keszler ◽  
Tejal Deodhar ◽  
Nihan Nugay ◽  
Joseph P. Kennedy
Keyword(s):  
Cationic Polymerization ◽  
Low Cost ◽  
Living Cationic Polymerization ◽  
Bifunctional Initiators
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