本研究以結晶性高分子PCL[poly(ε-caprolactone)]與液晶小分子8OCB(4-cyano-4’-octyloxy biphenyl -carbonitrile)為材料進行其混摻系統的熱行為觀察及相行為之研究。 研究之主要工具為DSC；利用重複的升降溫程序，獲得各種組成在同初始狀態下之相變化。DSC的研究發現PCL在8OCB介入時會形成熔融溫度不同之晶體；本研究也透過小角度X光散射儀(small-angle X-ray scattering, SAXS)及大角度X光散射儀(wide-angle X-ray scattering, WAXS)觀察晶體或液晶之結構特徵與隨溫度之變化；並藉由正交偏光顯微鏡(cross-polarized optical microscopy)得知樣品在升溫過程中相型態的變化，將其結果與DSC比對，做出PCL與8OCB混摻系統的相圖。 本研究同時利用不同分子量的PCL與8OCB混合，藉以探討PCL分子量大小對混摻系統的影響。發現分子量越小的PCL在混摻系統中得到的相轉移溫度也越低。 The thermal and phase behavior of a crystalline polymer, poly (ε-caprolactone), PCL, and a small molecular-weight liquid crystal, 4-cyano-4’-octyloxy biphenyl-carbonitrile, 8OCB, and their blends was investigated in this study. By repetition of heating and cooling to the blends in differential scanning calorimeter, the heating history was eliminated and the reproducible initial state was established for studies of phase changes. The investigation discovered that the crystallization behavior of PCL is severely interfered by the presence of 8OCB. By using small-angle X-ray scattering and wide-angle X-ray scattering, the characteristics of crystalline and liquid crystalline behavior and phase change of the PCL /8OCB mixture upon temperature changes were also observed. The phase diagram of 8OCB/PCL mixture was determined by combinatory observations of DSC and cross polarized optical microscopy, which in addition provided the changes in morphology during melting and crystallization processes. The effect with molecular-weight of PCL to the mixtures was studied by using different molecular-weights of PCL. The results showed that PCL of lower molecular-weight gave lower phase transition temperature.
