Synthesis, characterization and thermal properties of metaloquinolate-containing polymers

The monomer, 5-methyl(2-methacryloylethyloxy)-8-quinolinol(HEMA-CH₂-Hq), which possesses both double bond and 8-hydroxyquinoline groups, was synthesized from 2-hydroxyethyl methacrylate (HEMA) and 5-chloromethyl-8-quinolinol hydrochloride. The model polymer with 8-hydroxyquinoline ligands was obtained by free-radical copolymerization with styrene. So metaloquinolate (AlQ₃, ZnQ₂)-containing polymers are prepared by coordinating reaction with di(8-hydroxyquinoline) aluminum(AlQ₂) chelates or mono(8-hydroxyquinoline) zinc(ZnQ) chelates without cross-linking. Both polymer and polymer complexes were analyzed by FT-IR, UV-vis, DSC, TGA and photoluminescence spectroscopies. They are soluble in common solvents and easy to form films. The use of AlQ₂ and ZnQ avoided the cross-linking caused by the AlQ₃, ZnQ₂ formation between different polymer chains. High glass transition temperature, good thermal stability, and strong yellow-green fluorescence were observed for the prepared polymers. These polymers were expected to have the potential application in yellow-green OLEDs.