Precise synthesis of a rod-coil type miktoarm star copolymer containing poly(n-hexyl isocyanate) and aliphatic polyester

Abstract

Well-defined hydroxyl end-functionalized poly(n-hexyl isocyanate), PHIC-(OH)(2) and PHIC-(OH)(3), as rod-type macroinitiators were synthesized by the Cu-catalyzed azide-alkyne cycloaddition reactions of azido end-functionalized PHIC with ethynyl alcohol derivatives. The PHIC-(OH)(2) and PHIC-(OH) 3 were suitable macroinitiators for the ring-opening polymerization of L-LA and epsilon-CL leading to the synthesis of novel rod-coil type miktoarm star copolymers, PHIC-b-PLLA(2), PHIC-b-PLLA(3), PHIC-b-PCL2, and PHIC-b-PCL3, with controlled molecular weights, narrow polydispersities, and controlled arm numbers. Additionally, the thermal and solution properties of the obtained miktoarm star copolymers along with the corresponding block copolymers, PHIC-b-PLLA and PHIC-b-PCL, were characterized by TGA, DSC, and DLS analyses.