posted on 2014-08-12, 00:00authored byIkhlas Gadwal, Selmar Binder, Mihaiela
C. Stuparu, Anzar Khan
A new synthesis of hyperbranched
polymers through proton transfer
polymerization of thiol and epoxide groups is presented. For this,
an AB2 monomer bearing two epoxides and a thiol groups
is synthesized. Base-catalyzed proton transfer polymerization of this
monomer led to the formation of a polythioether-based hyperbranched
polymer with a 65–69% degree of branching and carrying about
2% of disulfide-based structural defects. This polymer contained two
reactive sites, a hydroxyl group and an epoxide unit, distributed
throughout the branched scaffold. The epoxide groups could be employed
in anchoring an alkyl, aryl, or ethylene oxide chain through a thiol–epoxy
reaction, while the hydroxyl groups produced during the polymerization
and the first functionalization reactions could be engaged in attaching
positively charged primary ammonium groups to the branched backbone.
These sequential postpolymerization modifications transformed the
general dual-reactive scaffold into dual-functionalized hyperbranched
materials with potential utility in the arena of gene delivery applications.