Abstract:
TPA-functionalized prepolymer (
iPrTPA-PrePBO,
tBuTPA-PrePBO) was synthesized by treating 4,4'-dicarbonylchloride-4''-isopropyltriphenylamine (
iPrTPADC) and 4,4'-dicarbonyl chloride-4''-tertbutyltriphenylamine (
tBuTPADC) with 4,6-di(tertbutyldimethylsilylamino)-1,3-di(tertbutyldimethylsiloxy)benzene (TBS-DAR), respectively. Then, a thermal cyclization reaction was carried out to obtain two benzoxazole polymers containing electron-donating triphenylamine groups (
iPrTPA-PBO,
tBuTPA-PBO). The prepolymers and benzoxazole polymers were characterized by nuclear magnetic resonance spectroscopy(
1H-NMR) and Fourier transforminfrared spectroscopy (FT-IR). Thermogravimetry (TG), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and fluorescence spectroscopy were used to analyze the solubility, thermal and photophysical properties of the polymers. The results showed that the two prepolymers had excellent solubility in conventional solvents, and the polymers after thermal cyclization reaction also had moderate solubility in solvents with a high boiling point such as dimethyl sulphoxide. The polymers existed in nitrogen atmosphere and air showed excellent thermal stability with a temperature above 500 ℃. Photophysical studies showed that polymers had higher fluorescence quantum yields than the conventional PBO, and their band gaps (about 2.0 eV) were close to the semiconductor.