Photoorientation in hydrogenbonded blends of liquidcrystalline polymers with a lowmolecular photochromic dopant

A series of hydrogenbonded blends of nematic liquidcrystalline copolymers with a lowmolecular photochromic dopant and their covalent analogs were prepared. Their phase behavior and photooptical properties were studied. The introduction of a dopant increases considerably the isotropization temperatures of the systems. A comparative study of photoorientation processes in the blends and copolymers analogous to them was carried out. The induced dichroism in covalent systems is more pronounced than in similar hydrogen� bonded blends.