title: Star-shaped PHB-PLA block copolymers: immortal polymerization with dinuclear indium catalysts.
abstract: The first example of a one-component precursor to star-shaped polyesters, and its utilization in the synthesis of previously unknown star-shaped poly(hydroxybutyrate)-poly(lactic acid) block copolymers, is reported. A series of such mono- and bis-benzyl alkoxy-bridged complexes were synthesized, fully characterized, and their solvent dependent solution structures and reactivity were examined. These complexes were highly active catalysts for the controlled polymerization of β-butyrolactone to form poly(hydroxybutyrate) at room temperature. Solution studies indicate that a mononuclear propagating species formed in THF and that the dimer-monomer equilibrium affects the rates of BBL polymerization. In the presence of linear and branched alcohols, these complexes catalyze well-controlled immortal polymerization and copolymerization of β-butyrolactone and lactide.
authors.affiliation: Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada. mehr@chem.ubc.ca.
authors.forename: I
authors.initials: I
authors.lastname: Yu
authors.forename: T
authors.initials: T
authors.lastname: Ebrahimi
authors.forename: S G
authors.initials: SG
authors.lastname: Hatzikiriakos
authors.forename: P
authors.initials: P
authors.lastname: Mehrkhodavandi
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D006885:Hydroxybutyrates / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D011091:Polyesters; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*
chemical_list: D006885:Hydroxybutyrates; D011091:Polyesters; D011108:Polymers; D007204:Indium; D019344:Lactic Acid; C033616:poly(lactide)