title: Dynamic-covalent macromolecular stars with boronic ester linkages.
abstract: Macromolecular stars containing reversible boronic ester linkages were prepared by an arm-first approach by reacting well-defined boronic acid-containing block copolymers with multifunctional 1,2/1,3-diols. Homopolymers of 3-acrylamidophenylboronic acid (APBA) formed macroscopic dynamic-covalent networks when cross-linked with multifunctional diols. On the other hand, adding the diol cross-linkers to block copolymers of poly(N,N-dimethylacrylamide (PDMA))-b-poly(APBA) led to nanosized multiarm stars with boronic ester cores and PDMA coronas. The assembly of the stars under a variety of conditions was considered. The dynamic-covalent nature of the boronic ester cross-links allowed the stars to reconfigure their covalent structure in the presence of monofunctional diols that competed for bonding with the boronic acid component. Therefore, the stars could be induced to dissociate via competitive exchange reactions. The star formation-dissociation process was shown to be repeatable over multiple cycles.
authors: Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314, USA.
authors: Abhijeet P
authors: AP
authors: Bapat
authors: Debashish
authors: D
authors: Roy
authors: Jacob G
authors: JG
authors: Ray
authors: Daniel A
authors: DA
authors: Savin
authors: Brent S
authors: BS
authors: Sumerlin
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry*; D001897:Boronic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry*; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: C419826:3-acrylamidophenylboronic acid; D000178:Acrylamides; D001897:Boronic Acids; D003432:Cross-Linking Reagents; D004952:Esters; D046911:Macromolecular Substances; C429790:poly(N,N-dimethylacrylamide)