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 poling (TP) of a new polyester with rigid main chain and disperse red 1 (DR1) molecules in the side chain (DR1-polyester). The experimental findings are discussed within the framework of our phenomenological theory of the PIP process. The molecular order created by TP is more efficient and more stable than that created by PIP and shows that PIP cannot induce a conformational change in the rigid main chains of this DR1-polyester. This may originate from the importance of the free volume in the DR1-polyester or from the inability of the main chains to move with the photoinduced movement of the azo chromophores they are covalently linked to. The evolution of the polar orientation during PIP is probed by the electrooptic Pockels effect using an attenuated total reflection setup.