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題名 | Liquid Crystalline Epoxy Resins=液晶環氧樹脂 |
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作者姓名(中文) | 林唯芳; 陳凱琪; 曾效沂; | 書刊名 | 國立臺灣大學工程學刊 |
卷期 | 77 1999.10[民88.10] |
頁次 | 頁73-84 |
分類號 | 440.34 |
關鍵詞 | 環氧樹脂; 硬化; 熱性; 液晶環氧樹脂; Liquid crystalline epoxy; Biphenyl; Azomethine; Thermal properties; Rigid rod; Crosslinking network; |
語文 | 英文(English) |
中文摘要 | 我們探討偶氮烷氰及連苯等液晶環氧樹脂固化後的物性。其分別與酸 酐類 (methyl cyclohexane 1, 2-dicarboxylic anhydride, MCHDA)、胺類 (sulfanilamide, SAA) 硬化劑以等當量比 (stoichiometric amount) 反應固化。以微 差熱分析儀DSC動態升溫的方式找出硬化的條件,並以熱重分析儀 (TGA)、動 態機械分析儀 (DMA)、熱機械分析儀 (TMA) 探討網狀結構的熱性質。X-ray繞 射探討其結晶性。液晶環氧樹脂較商業用對酚型環氧樹脂有較佳的熱性、電性及 機械性。在熱裂解行為方面,偶氮烷氰及連苯液晶環氧樹脂有高的熱裂解溫度, 且在高溫 (450°C) 時的殘餘量大。連苯╱胺類系統有最高的玻璃轉移溫度 (Tg):218.5°C,及最小的熱膨脹係數 (CTE):��1 = 20.76�慆/m°C。X-ray繞射圖 譜顯示連苯╱胺類系統固化後仍保有液晶相,其高度規則性分子排列結構展現了 較佳的熱性質。 |
英文摘要 | We have investigated physical properties of two liquid crystalline epoxies such as azomethine epoxy and biphenol epoxy. The resins were cured stoichiometrically via sulfanilamide and methyl cyclohexane 1, 2-dicarboxylic anhydride respectively. Differential scanning calorimetry, thermal gravimetric analysis, dynamic mechanical analysis, thermal mechanical analysis and X-ray diffraction were used to evaluate the physical properties of the cured resins. They have shown improved thermal, mechanical and electrical properties as they compared with bisphenol A epoxy and tetramethyl biphenyl epoxy. Among the resins that were studied, azomethine epoxy cured with sulfanilamide has the lowest weight loss (39%) at 450°C; biphenol epoxy cured with sulfanilamide has the highest glass transition temperature of 219°C and the lowest coefficient of thermal expansion of 20.8�慆/m°C. The X-ray study revealed that the biphenol epoxy-sulfanilamide system has a highly ordered smectic liquid crystalline network. |
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