Facile synthesis and self-assembly of multihetero-arm hyperbranched polymer brushes

A facile methodology was presented for scalable synthesis of hyperbranched-star polymers with tens of hydrophilic and hydrophobic hetero-arms, in merely two steps starting from monomers. Self-condensing atom transfer radical polymerization (SC-ATRP) of a clickable initiator-monomer (click-inimer), 3-azido-2-(2-bromo-2-methylpropanoyloxy) propyl methacrylate, resulted in a hyperbranched polymer with azido and bromo multihetero-groups. Subsequently orthogonal one-pot grafting onto azide-alkyne click coupling and grafting from ATRP with the core of hyperbranched polymer afforded targeted miktoarm globular binary brushes. The brushes could readily assemble into superstructures of 150-300 nm spheres and micro-scale sheets. Furthermore, hyperbranched copolymer possessing azido, hydroxyl and bromo trihetero-groups were synthesized by self-condensing atom transfer radical copolymerization of the click-inimer and 2-hydroxyethyl methacrylate (HEMA). Hyperbranched trinity brushes were then facilely prepared via a one-pot multigrafting strategy by a combination of click chemistry, esterification, and ATRP. The trinity brushes could assemble into superstructures of micron-scale dendritic tubes.