| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.157 |
| 발표분야 | 고분자 합성 |
| 제목 | Novel T-type Nonlinear Optical Polyurethanes and Their Properties |
| 초록 | Nonlinear optical (NLO) polymers are considered as a good candidate for making electro-optic (EO) devices, mainly because they offer many advantages.1 In the developments of NLO polymers for EO device applications, stabilization of electrically induced dipole alignment is important. Polyurethane matrix forms extensive hydrogen bond between urethane linkage and increases rigidity preventing the relaxation of induced dipoles.2 Physically crosslinked systems via hydrogen bonds have the advantages such as homogenity and good processability relative to the chemically crosslinked systems. In this work we prepared novel polyurethanes containing 2,5-dioxybenzylidenemalononitrile. 2,5-Di-(2-hydroxyethoxy)benzylidenemalononitrile (3) was prepared by hydrolysis of 2,5-di-(2-vinyloxyethoxy)benzylidenemalononitrile (2). Diol 3 was condensed with 2,4-toluenediisocyanate and 3,3-dimethoxy-4,4-biphenylenediisocyanate to yield novel T-type polyurethanes (4-5) containing 2,5-dioxybenzylidenemalononitrile group as a nonlinear optical (NLO) chromophore, which constitutes a part of the polymer backbone (Scheme 1). The resulting polyurethanes 4-5 were soluble in common organic solvents such as acetone and DMF. Polymers 4-5 showed a thermal stability up to 250oC in TGA thermograms with Tg values obtained from DSC thermograms in the range of 119-146oC (Table 1). The second harmonic generation (SHG) coefficients (d33) of poled polymer films at 1064 cm-1 fundamental wavelength were around 5.82 x 10-9 esu. The dipole alignment exhibited high thermal stability up to Tg, and there was no SHG decay below 140oC because of the partial main-chain character of the polymer structure, which was acceptable for nonlinear optical device applications. Scheme 1. Synthesis of Polymers 4-5. Table 1. Thermal properties of polymers 4-5 ----------------------------------------------------------- Polymer Tg, oC Degradation temp, oC Residue at ------------------------------ 800oC, % 5%-loss 20%-loss 40%-loss ----------------------------------------------------------- 4 119 281 306 402 40.2 5 146 305 372 372 23.7 ----------------------------------------------------------- References 1. D. M. Burland, R. D. Miller, and C. Walsh, Chem. Rev., 94, 31 (1994). 2. H. Y. Woo, K. S. Lee, and H. K. Shim, Polym. J., 32, 8 (2000). |
| 저자 | 이주연, 방한배 |
| 소속 | 인제대 |
| 키워드 | Nonlinear optics (NLO); polyurethanes; differential scanning calorimetry (DSC); thermogravimetric analysis (TGA); atomic force microscopy (AFM); SHG coefficient; relaxation of dipole alignment |
