Synthesis And Property Of The 8-hydroxyquinoline-conaining Polymer

Two novel electroluminescent polymers containing 8-hydroxyquinoline groups were prepared in this research. The resulting polymers were coordinated with metal ions to form polymeric complexes. The chemical structure and luminescent properties of the polymeric complexes were initially studied. First, a new functional monomer, namely 5-allyoxymethyl-8-hydroxyquinoline was prepared by reaction between 5-chloromethyl-8-hydroxyquinoline and allylethanol. Then the polymerisable monomer was copolymerized with styrene to prepare the copolymer of 5-allyoxymethyl-8-hydroxyquinoline and styrene under the initiation of AIBN. The copolymer was coordinated with Al³⁺,Mg²⁺,Zn²⁺ to prepare the polymeric complexes. Then 8-hydroxyquinoline-end-capped polystyrene was obtained by atom transfer radical polymerization routine(ATRP) . The initiator, 5-chloromethyl-8-acetoxyquinoline was prepared by acetylation of 5-chloromethyl-8-hydroxyquinoline with acetic anhydride under reflux. Styrene was polymerized by ATRP with the initiator system consisting of Cu(â… )Cl/5-chloromethyl-8-acetoxyquinoline/ 2-2'Bipyridine. The end-capped polysty -rene with free 8-hydroxyquinoline group was obtained by hydrolysis in aqueous THF with dilute NaOH solution. The purified polymer was coordinated with the ions of Al³⁺, Mg²⁺,Zn²⁺ to prepare the polymeric complexes. The chemical structure of the polymers and the polymeric complexes were characterized by infrared absorption spectroscopy, ultraviolet absorption spectroscopy and nuclear magnetic resonance spectroscopy. The thermal performance of the polymers and the polymeric complexes were studied by thermogravimetry analysis. The experimental results indicate: (1) Two kinds of polymer containing 8-hydroxyquinoline group were successfully prepared by normal free radical copolymerization and TARP methods. These polymers can coordinate with metal ions to form stable polymeric complexes.. (2) All polymers have excellent thermal stability under nitrogen atmosphere and initial weight-loss temperature higher than 300℃. All polymeric complexes can dissolve in dichloromethane, tetrahydrofuran and other common organic solvent and this solubility will facilitate the device-making procedure. (3) Strong fluorescent emission between 450nm and 550nm were observed of all polymeric complexes when these polymeric complexes were irradiated with ultraviolet rays. These polymeric complexes might be potential photoluminescent or electroluminescent materials with excellent film-forming property.