Functional Photochromic Methylhydrosiloxane- Based Side-Chain Liquid-Crystalline Polymers

A new azobenzene-group-containing monomer and several respective functional side-chain polymers grafted on a methylhydrosiloxane backbone (with two different degrees of polymerization; with and without the addition of a photoreactive benzophenone derivative) are designed, synthesized, and characterized. The resulting materials clearly show self-assembly behavior and possess a nematic liquid-crystal phase over a broad temperature range, which extends below 0 degrees C. The optical properties of these new photochromic liquid-crystalline materials are determined from the absorbance spectra of oriented samples and by photoinduced birefringence studies. The results indicate a considerable dichroism of the side-chain liquid-crystalline polymers (SCLCPs), and hence demonstrate their potential applicability for optical storage.