Hydrogen-bonded liquid crystalline polymers containing poly(4-vinylpridine) and dendron-like side chains: Fromlamellar to columnar phase

We investigated the phase behavior of a series of supramolecular polymer complexes P4VP(nCTB)x in which poly(4-vinylpyridine) (P4VP) is hydrogen-bonded with dendron-like small moleculescontaininga phenolic end group (nCTB, n = 6,10,12,14). Supramolecular lamellar and hexagonal columnar (ΦH) structures were investigated via small angle X-ray scattering (SAXS), polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The stability of the lamellar and ΦH phases is dependent on the blending ratio of nCTB per vinylpyridine unit (x), alkyl tail length (n) and thermal treatment. The P4VP(6CTB)x exhibit only a poorly ordered lamellar phase. Upon increasing x, the phase structure of the polymer complexes (n = 10, 12, 14) can transform from the lamellar to the ΦH phase. As a result of the thermal dynamic nature of hydrogen bond and the conformation changing of P4VPduring the thermal annealing, a non-reversible order-to-order transition from lamellar to ΦH phase appears when the volume fraction of the alkyl tails is 0.56–0.58.