The integration of an "X" type dendron into polymers to further improve the comprehensive NLO performanceElectronic supplementary information (ESI) available: Synthesis of compounds; NMR spectra; UV-vis spectra of solvents, TGA thermograms; UV-vis spectra of thin films before and after poling; NLO decay curves. See DOI: 10.1039/c5py00961h

Two linear polymers ( P1 , P2 ) and one dendronized hyperbranched polymer ( P3 ) were designed and synthesized, by utilizing an "X" type dendrimer as the basic construction block, which contained five nitro-based azo chromophore moieties. These polymers inherited the high NLO performance from their "X" monomers, however they demonstrated much better NLO thermal stability. After being poled under the optimized poling conditions, P1 exhibited a d 33@1064 nm value of 151 pm V −1 , a d 33@1950 nm value of 38 pm V −1 and a T 80% of 117 °C; for P2 , the d 33@1064 nm value was 162 pm V −1 with a d 33@1950 nm value of 41 pm V −1 and a T 80% of 132 °C, while for P3 , the d 33@1064 nm value was 141 pm V −1 , with a d 33@1950 nm value of 43 pm V −1 and a T 80% of 131 °C. Three polymers were designed and synthesized, by utilizing an "X" type dendrimer containing five nitro-based azo chromophore moieties, which exhibit good processability and good nonlinear optical performance, especially for NLO thermostability.