Synthesis and photochromic behavior of methylmethacrylate copolymers having anils as pendant

Methylmethacrylate copolymers (SAn-MMA) appending the 4-methacryloxyalkyl-N -(4-methoxysalicyliden)anilines (SAn) unit with a different alkyl chain spa cer between the polymer backbone and the SAn unit were synthesized to inves tigate the photochromic behavior in the solid state. Photochromism was obse rved at 445 nm in all copolymer films under UV irradiation. The thermal dec ay reactions increased with increasing temperature, and the rate was five t o seven times slower than those of monomers blended in PMMA. The rate of th ermal decay reactions depended on the alkyl chain length of SAn: it decreas ed with decreasing alkyl chain spacer because of restriction of the thermal conformational change by the polymer backbone, whereas the difference in t he thermal decay reaction was small when the carbon number of the alkyl spa cer was > 10. (C) 2000 Elsevier Science B.V. All rights reserved.