Journal of Polymer Science Part A: Polymer Chemistry, Vol.45, No.1, 111-124, 2007
Tuning the optical properties of hyperbranched polymers through the modification of the end groups
Dye-capped, hyperbranched, conjugated polymers were prepared by the modification of the peripheral bromo end groups of the hyperbranched polymer core with a palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. The dye-modified, hyperbranched polymers had high molecular weights and displayed good solubility in common organic solvents such as tetrahydrofuran, toluene, and chloroform. The structure of the dye-modified, hyperbranched polymers was characterized by H-1 and C-13 NMR and elemental analysis. The thermal properties of five kinds of hyperbranched polymers were investigated with thermogravimetric analysis and differential scanning calorimetry. The optical properties of the dye-capped, hyperbranched polymers were investigated with ultraviolet-absorption and fluorescence spectroscopy. The hyperbranched structure could effectively reduce the aggregation of the peripheral dyes. The emission colors of the hyperbranched polymers could be easily tuned by end-group modification. (c) 2006 Wiley Periodicals, Inc==.