کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5191337 | 1381230 | 2005 | 7 صفحه PDF | دانلود رایگان |
A unique crystallization and melting behavior of a novel semicrystalline polyimide derived from 3,3â²,4,4â²-biphenyltetracarboxylic dianhydride and 1,4-bis(3-aminopropyl)piperazine were studied by differential scanning calorimetry (DSC) with and without temperature modulation and wide-angle X-ray diffraction (WAXD). Polymer samples isolated from a chloroform solution showed melting transitions in the DSC. However, WAXD traces showed crystallinity only after annealing above the glass transition, for about 2 h. For samples crystallized from the melt, crystallization could be achieved only in a narrow crystallization range of 200-220 °C, after 10 h. A maximum crystallinity of this polyimide was found to be 30%. Two distinct melting transitions were observed by DSC, which could be explained using a partial disordering-reorganization-final melting model.
Journal: Polymer - Volume 46, Issue 11, 11 May 2005, Pages 3831-3837