NEW PHOTORESPONSIVE (METH)ACRYLATE (CO)POLYMERS CONTAINING AZOBENZENEPENDANT SIDEGROUPS WITH CARBOXYLIC AND DIMETHYLAMINO SUBSTITUENTS .1.SYNTHESIS AND CHARACTERIZATION OF THE MONOMERS

New azobenzene-based (az.b.) monomers with CO2H (acid) or N(CH3)(2) (b asic) substituents were synthesized. For some of these compounds new s ynthetic routes had to be developed, especially for the az.b. monomers with a CO2H substituent (azoacids) where their synthesis, purificatio n and (thermal) characterization turned out to be rather difficult. Th e monomers with a N(CH3)(2) substituent (azobases) were rather easy to synthesize. but were unexpectedly sensitive to acidic moisture. When exposed to air, the originally yellow powders slowly turned green. Thi s problem was solved by addition of a small amount of piperidine to th e recrystallizing solutions. Satisfactory yields and purity were achie ved for all az.b. monomers. As could be expected from the molecular st ructure of the az.b. monomers, a liquid crystalline behaviour was foun d in a few cases. Copyright (C) 1996 Elsevier Science Ltd