胆固醇侧部双键改性衍生物的合成与表征

胆固醇C(3)-OH用乙酸酐酯化后,用间氯过氧苯甲酸将C(5)=C(6)双键氧化成环氧,再用甲基丙烯酸对形成的环氧进行开环,得到带有双键的新型胆固醇单体。新型单体在冷冻-抽真空-通氮气循环四次后封管的条件下进行聚合,得到了相应的聚合物。用核磁共振(1H-NMR)、红外光谱(FT-IR)和单晶衍射研究了单体及聚合物的化学结构及组成,从单晶照片中可以直观地看到各个取代基的空间朝向。用差示扫描量热(DSC)、偏光显微镜(POM)和热重分析(TGA)对其热性能及晶体形态进行了研究和观察。实验结果显示,该新型聚合物具有优异的耐热性,初始分解温度高于320℃,可在耐热材料方面得到应用。

Synthesis and Characterization of Cholesteric Derivatives Based on the Side Double Bonds

C(3)-OH of cholesterol was esterified by acetic anhydride,and then C(5)=C(6) double bond was oxidated to epoxide using m-chloroperoxybenzoic acid.After that, methacrylic acid was used to open the epoxide,the monomer bearing double bonds was synthesized.Polymers based on cholesterol were obtained by polymerizing the corresponding monomer which was purged with nitrogen and subjected to four freeze-thaw cycles and sealed under vacuum.1H nuclear magnetic resonance spectrum(1H-NMR),Fourier transform infrared spectra(FT-IR) and single crystal diffractometer were used to characterize chemical structures and composition of the synthesized monomers and polymers.The picture of single crystal shows the orientation space of every substituent group.Differential scanning calorimetry(DSC),thermogravimetric analysis(TGA) and polarizing microscope(POM)were used to characterize the thermal properties and crystal morphology,respectively.The results show that this polymer has excellent thermal properties,and the initial decomposition temperature is higher than 320 ℃,and can be used as heat-resisting material.