Synthesis and characterization of NLO polymers containing dendritic structures

POLY 151

Yung Chung Chen, d9365016@mail.nchu.edu.tw, Shenghong A. Dai, and Ru-Jong Jeng, rjjeng@dragon.nchu.edu.tw. Department of Chemical Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, 402, Taiwan
To investigate the effects of the dendritic structures on the EO-coefficients and thermal stability of the NLO materials, a bifunctional compound MIA, (4-isocyanato-4_(3,3-dimethyl-2,4-dioxo-acetidino)-diphenylmethane) was used as building block to synthesize a series of chromophore-containing dendritic structures (G0.5-G3). These structures were prepared by the convergent method based on the selectivity of isocyanate group on one end of MIA and azetidine-2,4-dione on the other. The glass transition temperatures of G1-G3 dendrons were in the range of 76-116 oC, and only G0.5 dendron exhibited a Tm at 98 oC. The 5% weight loss temperatures were in the range of 181-259 oC in nitrogen. Moreover, the guest-host NLO-active system was prepared from blending high Tg polyimides with the dendritic structures (20 wt% loading). The EO coefficients were ranged from 6.0 to 12.0 pm/V. The r33/dye content ratio increased with increasing generation of dendron containing PI sample. Excellent temporal stability at 80 oC was obtained. Moreover, waveguide properties for higher generation of dendron-containing NLO polymer (3.2 – 4.9 dB/cm) were also measured.