Enantioselective Living Coordinative Chain Transfer Polymerization: Production of Optically Active End-Group-Functionalized (+)- or (−)-Poly(methylene-1,3-cyclopentane) via a Homochiral C1-Symmetric Caproamidinate Hafnium Initiator

ACS Catalysis ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8496-8502
Author(s):  
Mark A. Wallace ◽  
Peter Y. Zavalij ◽  
Lawrence R. Sita
Keyword(s):  
Chain Transfer ◽  
Optically Active ◽  
Chain Transfer Polymerization ◽  
End Group

scholarly journals Piezoelectrically Mediated Reversible Addition-Fragmentation Chain Transfer Polymerization

2022 ◽  
Author(s):  
Chengqiang Ding ◽  
Zhengbiao Zhang ◽  
zhao wang
Keyword(s):  
Chain Transfer ◽  
Uv Curing ◽  
Composite Resins ◽  
Chain Extension ◽  
Light Penetration ◽  
Reversible Addition ◽  
Good Potential ◽  
Chain Transfer Polymerization ◽  
Trans Ducer ◽  
End Group

A well-controlled piezoelectrically mediated reversible addition-fragmentation chain transfer polymerization (piezo-RAFT) was carried out under ultrasound agitation with piezoelectric ZnO nanoparticles as the mechano-chemical trans-ducer. The resulting polymer had predictable molecular weight, high end-group fidelity, low dispersity, and capacity for chain extension. This chemistry was further adopted in curing composite resins to circumvent the light penetration limit of UV curing. This work opened a new avenue of piezoelectrically mediated chemistry and showed its good potential in curing applications.

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.

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