Hyperbranched polymer-cored star polyfluorenes as blue light-emitting materials

Hyperbranched polymer-cored star polyfluorenes with high molecular weights and narrow molecular weight distribution were prepared by palladium-catalyzed one-pot Suzuki polycondensation of multi- functional cores and an AB-type monomer. The optical, electrochemical and thermal properties of the hyperbranched polymer-cored star polymers were investigated. These polymers exhibited good ther- mal and color stability in solid state, and there was no significant blue-green emission after the poly- mers had been annealed in air for 2.5 h. Their three-dimensional hyperbranched structures could ef- fectively reduce the aggregation of the peripheral rigid linear conjugated polyfluorene chains.