Poly(4-vinylpyridine)-block-poly(N-acryloylpiperidine) diblock copolymers: synthesis, self-assembly and interaction

Controlled radical polymerization of 4-vinylpyridine (4VP) and N-acryloylpiperidine (API) by the RAFT process allowed preparation of well-defined double hydrogen bond accepting P4VP-b-PAPI diblock copolymers. The miscibility of this new monomer pair was studied via a random copolymer blend approach and resulted in a Flory-Huggins interaction parameter chi(4VP,API) approximate to 0.03, which is higher than the commonly used styrene/MMA couple, but lower compared to styrene/isoprene. This value was found to support the bulk phase behavior of a series of diblock copolymers as evidenced by SAXS and TEM. Highly ordered structures, including cylinders, lamellae and spheres, were identified in these materials, even in diblocks of higher molecular weight and broader distribution, while a disordered morphology was indeed observed in a symmetric, low molecular weight analogue.