Synthesis and property investigations: A partially conjugated hyperbranched polymer for light-emitting application

An A2 + B4 approach was adopted to synthesize a partially conjugated hyperbranched polymer HPBPV in which rigid fluorescent conjugated segments and flexible non-conjugated spacers arranged alternately through ether bonds in the skeleton. FT-IR, NMR and elemental analysis were employed to identify the structure of the monomers and polymer. The optimized conformation of HPBPV (one generation) demonstrated three-dimensional structure instead of two-dimensional structure of the fully conjugated hyperbranched polymer. Property investigations revealed that the polymer had good solubility in common organic solvents, good thermal stability and high glass transition temperature. It is also found that the end groups have an obvious impact on the solubility and thermal properties of the polymers, which was discussed in detail in the paper. The relative PL quantum efficiency of the polymer in dilute chloroform solution amounts to 62%. A brief LED device was fabricated and its electroluminescent performance was studied.