scholarly journals End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water

2014 ◽  
Vol 10 ◽  
pp. 680-691 ◽  
Author(s):  
Sebastian Reinelt ◽  
Daniel Steinke ◽  
Helmut Ritter
Keyword(s):  
Free Radical ◽  
Cloud Point ◽  
Chain Transfer ◽  
Sulfur Oxidation ◽  
Degree Of Polymerization ◽  
Functionalized Polymers ◽  
Solution Temperature ◽  
Radical Chain ◽  
Chain Transfer Polymerization ◽  
End Group

In this work we report the synthesis of thermo-, oxidation- and cyclodextrin- (CD) responsive end-group-functionalized polymers, based on N,N-diethylacrylamide (DEAAm). In a classical free-radical chain transfer polymerization, using thiol-functionalized 4-alkylphenols, namely 3-(4-(1,1-dimethylethan-1-yl)phenoxy)propane-1-thiol and 3-(4-(2,4,4-trimethylpentan-2-yl)phenoxy)propane-1-thiol, poly(N,N-diethylacrylamide) (PDEAAm) with well-defined hydrophobic end-groups is obtained. These end-group-functionalized polymers show different cloud point values, depending on the degree of polymerization and the presence of randomly methylated β-cyclodextrin (RAMEB-CD). Additionally, the influence of the oxidation of the incorporated thioether linkages on the cloud point is investigated. The resulting hydrophilic sulfoxides show higher cloud point values for the lower critical solution temperature (LCST). A high degree of functionalization is supported by 1H NMR-, SEC-, FTIR- and MALDI–TOF measurements.

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.

Electron Transference in Free Radical Chain Transfer Reactions

Nature ◽  
1964 ◽  
Vol 202 (4933) ◽  
pp. 690-691 ◽  
Author(s):  
JAY K. KOCHI ◽  
DENNIS D. DAVIS
Keyword(s):  
Free Radical ◽  
Chain Transfer ◽  
Transfer Reactions ◽  
Radical Chain

Preparation of polystyrene brush film by radical chain-transfer polymerization and micromechanical properties

2008 ◽  
Vol 255 (5) ◽  
pp. 2295-2302 ◽  
Author(s):  
Jing Zhao ◽  
Miao Chen ◽  
Yanqing An ◽  
Jianxi Liu ◽  
Fengyuan Yan
Keyword(s):  
Chain Transfer ◽  
Radical Chain ◽  
Micromechanical Properties ◽  
Chain Transfer Polymerization

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.

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