Structure and photostability of metal-containing methyl methacrylate copolymers colored by Rhodamine 6G

The structure and photostability of ternary methyl methacrylate copolymers with methacrylic acid and metal (sodium, barium, lead, and erbium) methacry lates colored by Rhodamine 6G were studied. It was established that, unlike methyl methacrylate-methacrylic acid copolymer. metal-containing copolymer s and the dye incorporated into these copolymers are characterized by highe r photostability, which increases in a sequence Na1+ < Ba2+ < Pb2+ < Er3+, depending on the nature of the salt cation. In addition to the direct photo stabilizing action of salt groups, the observed effect can be related to th e structural features of the copolymers. In the above sequence, the structu re of the copolymers changes from linear to lightly cross-linked, the (ster eo)regularity of macromolecular chains increases, as shown for the sodium m ethacrylate copolymer, and the dimensions and number of the ordered supermo lecular structures grow. These changes create more favorable conditions for the dissipation and transfer of photoexcitation energy of macromolecules. It is demonstrated that lead and erbium methacrylate copolymers show promis e as laser-active media.