中文摘要：

以羟丙基纤维素（HPC）为原料，通过酯化反应合成了丙酰氧丙基纤维素（PPC），通过FT-IR表征其化学结构．以POM和DSC方法研究了产物的液晶相转变、织态结构及其影响因素．结果表明，产物PPC具有明显的热致液晶性能，且呈现出胆甾型液晶的彩色条纹织构；反应条件对产物丙酰基含量和液晶性能有显著影响，随反应温度提高和丙酰氯用量增加，产物丙酰基的取代度先增大，后趋于稳定；其相转变温度和温域随丙酰基取代度改变而相应变化，随丙酰基的取代度增大，产物的熔点降低，液晶温度范围变宽．

英文摘要：

Propoxy propyl cellulose （PPC） was synthesized by esterificafion with hydroxypropyl celluose（HPC） as raw material. The chemical structure of PPC was characterized by FT IR. The liquid crystalline phase transition and the texture of PPC liquid crystal, and the influencing factors were studied by POM and DSC. The results showed that PPC was a thermotropic liquid crystal and displayed the cholesteric banded texture. The reaction conditions had the distinct effects on the prepoxy content and liquid crystal property of PPC, with the reaction temperature and content of prepionyl chloride increased, the degree of substitution （DS） of prepoxy increased at the beginning, then trended to steady. The transition temperature and range of liquid crystalline phase were changed with the DS of prepoxy, as the DS of propoxy increased, the melt point decreased, and the liquid crystalline phase transition temperature range of PPC get wider.