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題名 | β-相聚偏二氟乙烯晶體結構與物性=Structure and Properties of β-from Crystalline Poly(Vinylidene Fluoride) |
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作者 | 廖文彬; 于裕正; Liau, W. B.; Yu, Y. J.; |
期刊 | 材料科學 |
出版日期 | 19961200 |
卷期 | 28:4 1996.12[民85.12] |
頁次 | 頁249-260 |
分類號 | 440.33 |
語文 | chi |
關鍵詞 | β-相聚偏二氟乙烯; 晶體結構; 分子力學方法; 物理性質; β-PVDF; Crystal structure; Molecular mechanics method; Properties; |
中文摘要 | 本文係以分子力學方法,在同時考慮高分子鏈內與高分子鏈間作用力下 模擬β-相聚偏二氟乙烯晶體結構並預測其熱力學、機械與介電等物性。計算結 果,β-相聚偏二氟乙烯晶體是由兩條平面鋸齒狀(planar-zigzag)的高分子鏈平行排 列在斜力晶系晶格內形成。單位晶胞三軸大小分別為a=0.863nm、b=0.477nm、 c=0.254nm:與實驗值a=0.847nm、b=0.490nm、c=0.256nm非常接近。位能較低的分 子鏈構形為平面鋸齒狀與Lando等所提一樣,但與Hasegawa所提稍為偏離平面鋸 齒狀的構形不同。分子鏈內氟原子間最近距離為0.254nm,小於兩個氟原子的凡 得瓦半徑之和。 預測出來的晶體定體積與定壓比熱值與實驗值吻合。軸方向的彈性係數則為 318GPa。介電常數則與另一種預測方式結果接近。 |
英文摘要 | In this paper, the crystal structure and properties of β-PVDF (Poly (vinylidene fluoride))have been studied by using the molecular mechanics method that simultaneously considers the intra- and inter-chain interactions. It is found that the unit cell of PVDF consists of two parallel planar-zigzag chains packing in an orthorhombic unit cell. The lattice constants of the unit cell are a=0.863nm, b=0.477nm, c=0.254nm. Those values are very close to the experimental values which are a=0.847nm, b=0.490nm, c=0.256nm. The lowest-energy chaincon formation is planar-zigzag which is the same as the one proposed by Lando et.. However ,it is different from the statistically deflected zig-zag which proposed by Hasegawa. The shortest distance between fluorine atoms is 0.254nm which is less than the sum of van der Waals radii (0.27nm). Also, the calculated heat capacities are close to the experimental results. The calculatedelastic constants. C�婀� is 318GPa. |
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