Synthesis of Well-Defined Star-Branched Polymers by Coupling Reactions of Polymer Anions Consisting of Two Polymer Chains with Chain-End-Multifunctionalized Polystyrenes with Benzyl Bromide Moieties

2003 ◽  
Vol 36 (16) ◽  
pp. 6081-6086 ◽  
Author(s):  
Akira Hirao ◽  
Yui Tokuda
Keyword(s):  
Benzyl Bromide ◽  
Polymer Chains ◽  
Branched Polymers ◽  
Coupling Reactions

Embedding multiple site-specific functionalities into polymer chains via nitrone-mediated radical coupling reactions

2011 ◽  
Vol 49 (10) ◽  
pp. 2118-2126 ◽  
Author(s):  
Edgar H. H. Wong ◽  
Martina H. Stenzel ◽  
Thomas Junkers ◽  
Christopher Barner-Kowollik
Keyword(s):  
Polymer Chains ◽  
Coupling Reactions ◽  
Multiple Site ◽  
Site Specific ◽  
Radical Coupling

Branching in Polymer Chains

1972 ◽  
Vol 45 (3) ◽  
pp. 519-545 ◽  
Author(s):  
V. A. Grechanovskii
Keyword(s):  
Molecular Weight ◽  
Breaking Strength ◽  
Strength Properties ◽  
Polymer Chains ◽  
Branched Polymers ◽  
Shear Stresses ◽  
Linear Polymers ◽  
Concentrated Solutions ◽  
Active Centers ◽  
Lower Viscosity

Abstract The branching that occurs in molecular chains leads to extensive changes of the physico-mechanical and technological properties of various polymers, as compared with the corresponding linear polymers. For example, branched divinylstyrene rubbers, polybutadienes, and other branched elastomers possess a low elasticity, breaking strength, etc. The decrease of strength properties and the change of the dynamic and mechanical properties with the increase of the degree of branching is characteristic for such thermoplastic polymers as polystyrene, polyethylene, polyvinyl chloride, etc. There also exist considerable differences in the rheological properties of linear and branched polymers. For example, at low loads (shear stresses) linear polymers and their melts flow like newtonian fluids and possess a lower viscosity as compared with branched polymers, whereas at high loads the character of flow deviates from that of a newtonian flow, so that the viscosity of a branched polymer is lower than that of a linear polymer or almost equal. Similar regularities have also been observed for concentrated solutions. Hence, the branching, together with the regularity of the structure of polymer chains, the molecular weight, and the molecular weight distribution, represents one of the most important molecular parameters of polymers. The branching occurs during polymerization and is caused essentially by a transfer of active centers to the polymer chain.

Altering the effectiveness of radical traps in atom transfer radical coupling reactions of polymer chains

Polymer ◽  
2017 ◽  
Vol 127 ◽  
pp. 66-76 ◽  
Author(s):  
Jessica P. Wu ◽  
Ching W. Pan ◽  
Katherine E. Heiler ◽  
Megan E. Ching ◽  
Eric S. Tillman
Keyword(s):  
Polymer Chains ◽  
Atom Transfer ◽  
Coupling Reactions ◽  
Radical Coupling ◽  
Radical Traps

Green synthesis of palladium nanoparticles via branched polymers: a bio-based nanocomposite for C–C coupling reactions

RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 32202-32211 ◽  
Author(s):  
Changyan Wu ◽  
Xinwen Peng ◽  
Linxin Zhong ◽  
Xuehui Li ◽  
Runcang Sun
Keyword(s):  
Green Synthesis ◽  
Heck Reaction ◽  
Palladium Nanoparticles ◽  
Recyclable Catalyst ◽  
Branched Polymers ◽  
Coupling Reactions ◽  
Natural Ligand

Renewable and sustainable CMH was the natural ligand for CMH–Pd(0) nanocomposite which was as an efficient and recyclable catalyst for Heck reaction.

Sign in / Sign up

Export Citation Format

Share Document