胆甾液晶弹性体的合成及液晶性能研究

Synthesis and property of cholesteric liquid crystalline elastomers

以胆甾液晶单体和向列液晶交联剂与含氢聚硅氧烷接枝聚合制备了一系列弹性体。通过红外光谱(FT IR)、核磁氢谱(1 H NMR)确定了液晶单体及弹性体的化学结构。通过差热扫描量热仪(DSC)、偏光显微镜(POM)以及X射线衍射研究了其介晶性质及液晶相行为。结果表明,弹性体的玻璃化转变温度随着向列液晶交联剂的加入先降低后升高。随着向列液晶交联剂的加入,系列弹性体的X射线衍射峰弥散,且最大反射波长略微变长,说明液晶分子间的有序性受到干扰。

A series of polysiloxane-based cholesteric liquid crystalline polymers were synthesized by a cholesteric monomer and a nematic crosslinking monomer. The chemical structures of the mono- mers and elastomers were confirmed by FT-IR and 1 H-NMR spectroscopy. Their mesomorphic proper- ties and phase behavior were investigated by differential scanning calorimetry（DSC）,polarizing optical microscopy（POM）, and X-ray diffraction measurements. With increase of mesogenic crosslinking corn- ponent in the polymers, both the temperature of glass transition and melting point change irregularly. The intensity of X-ray diffraction with increase of mesogenic crosslinking units spreaded, suggesting that the order between two neighbor liquid crystalline molecules disturbed by the mesogenic crosslink ing agents,and the maximum reflection bands shifted slightly to long wavelength.