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題名 | Synthesis and Properties of Reactive Smectic Polyester Oligomers=反應性距列聚酯寡聚合體的合成及性質 |
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作者 | 蔡宏斌; 李大剛; 蔡瑞禧; | 書刊名 | 宜蘭農工學報 |
卷期 | 15 1997.12[民86.12] |
頁次 | 頁135-148 |
分類號 | 346.28 |
關鍵詞 | 熱向性; 液晶聚合體; 距列; 反應性寡聚合體; 熱轉變; Thermotropic; Liquid crystalline polymers; Smectic; Reactive oligomers; Thermal transitions; |
語文 | 英文(English) |
中文摘要 | 反應性距例( P,P'-聯苯二甲酸戊二酯)酯寡聚合體係由P,P'-聯苯二甲酸二甲酯 與過量 1,5 - 戊二醇進行熔融聚縮合再於真空下抽出一些 1,5- 戊二醇而製得。 寡聚合體 的分子量可由 1,5- 戊二醇對 P,P'- 聯苯二甲酸二甲酯的添加莫耳比及 1,5- 戊二醇的抽 出量來加以控制。 寡聚合體以�� H NMR, DSC,偏光顯微鏡及 X- 射線繞分析研究其性質。 �� HNMR 光譜顯示 P,P'- 聯苯二甲酸二甲酯與 1,5- 戊二醇之間的酯交換反應接近完全, 因此,所得者為明確的 OH 終端基的寡聚合體。具有夠高分子量的聚 (P,P'- 聯苯二甲酸戊 二酯 ) 顯現雙向距列液晶相。 當分子量降低時,聚酯寡合體有形成單向距列液晶相的趨勢 。 由 DSC 降溫曲線可明顯的看出等向距列轉變。當分子量降低時,距列排列規則性顯著的 降低。 ined hydroxy-terminated oligomers were obtained. The molecular wight, affects the transitions significantly. With a high enough molecular weight, poly (pentamethylene p, p'-bibenzoate) exhibits an enantiotropic smectic phase. The polyester oligomers tend to exhibit a monotropic smetic phase as the molecular weight decrease. From the DSC cooling cruve, the isotropic-smecitic transition can be seen more clearly. As the moleculare weight decrease, the smecitc order decrease significantly. |
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