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

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 ε-CL leading to the synthesis of novel rod-coil type miktoarm star copolymers, PHIC-b-PLLA2, PHIC-b-PLLA3, 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.