title: Chain-growth click polymerization of AB2 monomers for the formation of hyperbranched polymers with low polydispersities in a one-pot process.
abstract: Hyperbranched polymers are important soft nanomaterials but robust synthetic methods with which the polymer structures can be easily controlled have rarely been reported. For the first time, we present a one-pot one-batch synthesis of polytriazole-based hyperbranched polymers with both low polydispersity and a high degree of branching (DB) using a copper-catalyzed azide-alkyne cycloaddition (CuAAC) polymerization. The use of a trifunctional AB2 monomer that contains one alkyne and two azide groups ensures that all Cu catalysts are bound to polytriazole polymers at low monomer conversion. Subsequent CuAAC polymerization displayed the features of a "living" chain-growth mechanism with a linear increase in molecular weight with conversion and clean chain extension for repeated monomer additions. Furthermore, the triazole group in a linear (L) monomer unit complexed Cu(I) , which catalyzed a faster reaction of the second azide group to quickly convert the L unit into a dendritic unit, producing hyperbranched polymers with DB=0.83.
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA).
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA).
authors.forename: Robert W
authors.initials: RW
authors.lastname: Graff
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA).
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA).
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (USA). hgao@nd.edu.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Gao
mesh_terms: D002384:Catalysis; D057930:Click Chemistry / Q000379:methods*; D015394:Molecular Structure; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers
keywords: CuAAC; chain growth; click chemistry; hyperbranched polymers; polymerization