Macromolecular Dyes by Chromophore-Initiated Ring Opening Polymerization of L-Lactide

End functionalized polylactides are prepared by ring opening polymerization ofL-lactide in the presence of stannous octoate (Sn(Oct)2). Three chromophores, 9H-carbazol-ethanol(CA), 9-fluorenyl-methanol (FM), and 2-(4-(2-chloro-4-nitrophenylazo)-N-ethylphenylamino)ethanol(Disperse Red 13, DR), are for the first time used as co-initiators in the polymerization process.The polymerization reaction is initiated by conventional thermal treatment, but in the case of FM,microwave-assisted polymerization is also carried out. CA and FM absorb and emit in the UVportion of the electromagnetic spectrum, whereas DR absorbs in the visible part. The obtainedend-capped polylactides derivatives show the same photophysical properties as the initiator, so theyare "macromolecular dyes" (MDs) that can be used "as synthesized" or can be blended withcommercial poly(lactic acid) (PLA). The blends of PLA with MDs have ultraviolet-visible (UV-Vis)absorption and fluorescence emission features similar to that of MDs and thermal properties typicalof PLA. Finally, migration tests, carried out onto the blends of PLA with MDs and PLA with freechromophores, show that MDs are less released than free chromophores both in solution and inthe solid phase.