Dendronized hyperbranched polymers containing isolation chromophores: design, synthesis and further enhancement of the comprehensive NLO performance

Dendronized hyperbranched polymer (DHP) combining the structure of a dendrimer and a hyperbranched polymer, is a new kind of polymer, with some advantages as summarized from the few examples reported so far. Herein, three second-order nonlinear optical (NLO) functional dendronized hyperbranched polymers, DHP-NN, DHP-NS and DHP-SS, were prepared in satisfactory yields through the click chemistry reaction, by using two kinds of low generation dendrimers as the monomers. Due to its particular branched structure, these DHPs with high molecular weights exhibit good solubility, processability, and good nonlinear optical performance. All the DHPs can keep their NLO performance at relatively high temperatures (∼100 °C). In particular, the introduced isolation chromophore could further enhance the thermostability of the NLO performance: DHP-NS and DHP-SS exhibit no obvious decay of their NLO coefficient when the thin films are heated to 125 °C.