非线性光学活性的侧链型聚丙二酸酯液晶的合成和性质

SYNTHESIS AND PROPERTIES OF NONLINEAR OPTICAL SIDE CHAIN LIQUID CRYSTALLINE POLYMALONATE

通过熔融缩聚法合成了含非线性光学活性硝基偶氮苯液晶基元的聚丙二酸酯侧链液晶聚合物 ,采用FTIR、NMR对其结构进行了表征 ,DSC确定其液晶转变温度 ,并用变温WAXD及偏光显微镜 (POM )研究其液晶性质 ,该聚合物为近晶型液晶聚合物 ,POM观察到典型焦锥织构 ,近晶相WAXD有对应层间距为2 74nm和 1 35nm的两个衍射峰 .聚合物旋涂膜经电晕极化 ,紫外光谱测试求得其取向序参数 =0 33 .

The orientational order of a liquid crystalline( LC)system is in favor of the alignment of nonlinear optical (NLO) units. If a NLO unit is:also a LC unit, the resulted liquid crystalline NLO polymer may possess a higher orientational order and therefore promote the nonlinear optical sensibility. A polymalonate side chain liquid crystalline (LC) polymer with a nonlinear optical nitro azobenzene type mesogenic unit has been synthesized by melt polycondensation, which was characterized by FTIR and H-1-NMR. The thermal transition temperatures and LC properties of the polymer were determined by DSC, polarized optical microscope(POM) and WAXD. A typical-smectic focal conic texture was observed under POM and two small sharp WAXD peaks corresponding to Bragg's spacings 2.74nm and 1.35nm appeared in the smectic phase, Moreover, spin-coating films of the polymer through corona poling possessed an orientational order parameter phi =0.33 calculated from UV measurements. But light scattering resulted from the crystallization of the polymer reduced the transparency of the polymer film and some small sharp peaks appeared in the UV spectra.