Preparation And Characterization For Hyperbranched Polyesteramides And Its Rare Earth Complexes

As part of our research effort to explore and develop desirable applications for hyperbranched polymer (HBP) in polymer processing realm, our recent efforts have focused on simplifying hyperbranched polyesteramides (HBPEA) synthesis process and functionalizing HBPEA. Re(III)-HBPEA complex synthesized by incorporating rare earth chloride (EuCl3-6H2O,SmCl3-6H2O) with HBPEA via dissolution-distillation process, which may show good apply effects in optical materials due to the complexation and integrating Re3+ magic properties to HBPEA unique properties. In such opinions, some work were been done as follows in this paper.A simplified method for syntheses of HBPEA has been developed based on the van Benthem approach. HBPEA polymers were successfully synthesized via melt copolymerization of diethanolamine and succine anhydride. Special structures with large numbers of branches and numerous terminal hydroxyl groups were demonstrated for the resultant polymers by FT-IR,1H NMR and 13C NMR spectra. The degree of branching (DB) of the polymers were determined to be 0.46-0.57 by 1H NMR or 13C NMR spectra. The peculiar structures result in low viscosities and high solubility of the polymers. Thermogravimetric analysis (TGA) revealed that the decomposition temperature of the polymers at 10% weight-loss temperature (Td10) were above 220℃in air. The resulting polymers fluoresce blue fluorescence in solid and in solution. The maximum excitation and emission wavelengths in DMSO solution are 332 nm and 415 nm, respectively. The effect of concentration of the polymer, pH of the medium, metal ion and solvents have also been investigated on the fluorescence characteristics of HBPEA. Blending nitrile rubber (NBR) with appropriate amount of HBPEA within 60～70℃resulted in better processability of the blends without observably changing the NBR dynamic rheological nature of preferential elasticity, according to the results of strain sweeps.Hyperbranched polyesteramide rare earth complexes has been prepared form rare earth chloride(RECl3-6H2O) and HBPEAs in alcohol solvent. The composition, structure and thermal properties of the resultant complexes were characterized by FT-IR,13C NMR and TGA. FT-IR and 13C NMR indicate that RE3+ ions can coordinate with HBPEA under the proposed conditon, and the sites of coordination primarily rest on the oxygen atoms from-CO-OH groups and-CO-NR-groups of the ligand. The thermal stability of rare earth complexes is a little inferior to that of HBPEAs. The results of fluorescence spectra analysis revealed that the triplet energy of HBPEAs ligand is in an appropriate level to transfer energy to RE3+ ions.A novelπ-conjugated HBPEAM ligand and its complex were synthesized. The chemical structures of the HBPEAM and complex were characterized by FT-IR,1H NMR, I3C NMR, TG and FS. FT-IR and I3C NMR indicate that the HBPEAM is coordinated to RE3+ ions, and chemical bonds are formed between RE3+ ions and the HBPEAM. The fluorescent spectra of the complex display that the characteristic narrow bands arise from intraconfigurational transitions of trivalent rare earth ions, corresponding to the emission form the Eu3+ ion. The lack of the broaden emission bands arising from the HBPEAM suggests that the efficient intramolecular energy transfer occurs from the HBPEAM to Eu3+ ions. Besides, The influences of pH and solvent on the fluorescence intensity of the complexes were also discussed.An europium complex containing acetylacetone (acac) ligands doped HBPEAM was synthesized. The chemical structures of the composites were characterized by FT-IR, TG and FS. The thermal stability of these composite were better than that of the pure europium complex. The fluorescent spectra show that the intensity of the 5D0-7F2 transition for Eu3+ in the composites is stronger than the pure europium complex. The lifetime of Eu(acac)3/HBPEAM composites is longer than Eu(acac)3.