Abstract
Photochromic compounds are able to change their absorption spectra when exposed to light or dark condition. This process is reversible when the photochromic moieties exist, as usually occurs, in two different forms, whose relative concentration depends on the wavelength of incident light. Polymers with side-chain photochromic groups have recently attracted a great deal of interest because the photoisomerisation of the chromophores can induce reversible variation of the macromolecular structure and hence their physical properties. Keywords: photochromic, polymeric materials