ROOM-TEMPERATURE PHOTOINDUCED POLING AND THERMAL POLING OF A RIGID MAIN-CHAIN POLYMER WITH POLAR AZO DYES IN THE SIDE-CHAIN

We report on room-temperature photoinduced poling (PIP) and thermal po ling (TP) of a new polyester with rigid main chain and disperse red 1 (DR1) molecules in the side chain (DR1-polyester). The experimental fi ndings are discussed within the framework of our phenomenological theo ry of the PIP process. The molecular order created by TP is more effic ient and more stable than that created by PIP and shows that PIP canno t induce a conformational change in the rigid main chains of this DR1- polyester. This may originate from the importance of the free volume i n the DR1-polyester or from the inability of the main chains to move w ith the photoinduced movement of the azo chromophores they are covalen tly linked to. The evolution of the polar orientation during PIP is pr obed by the electrooptic Pockels effect using an attenuated total refl ection setup.