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標題: 不同環境對聚對苯二甲酸乙烯酯質傳的影響
The Effect of different environments on the mass transport in POly(Ethylene Terephthalate)
作者: 蕭世宏
Shyh Horng, Shore
關鍵字: mass transport
出版社: 材料工程學研究所
摘要: 摘要 經過目前的研究,丙酮及乙酸乙酯 在聚對苯二甲酸乙烯酯Poly(Ethylene Terephthalate)(PET)中均有質傳 的現象;本文透過Fickian model(Case I)及Case II模型來研究此種質傳 的行為。大氣及真空退火的試片在不同的預熱環境下進行溶劑的吸收\反 吸收測 量,求出擴散係數D\擴散速率v並可量得溶解度之值。將lnD對絕 對溫度的倒數\lnv對絕對溫度的倒數及溶解度的對數與絕對溫度的倒數作 圖,可分別求出活化能;因此可以比較不同環境的影響。當PET吸收乙酸乙 酯後,經X光繞射及DSC分析的結果,有明顯的結晶產生。另外使用阿基米得 法量測密度,得知大氣下退火的試片均約等於真空退火的試片。Gibbs- Thomson 方程式可以解釋結晶的厚度與熔點的關係。試片在真空烘箱中預 熱所得的活化能可以跟泡水預熱的活化能作比較。
Abstract Acetone and ethyl acetate are used as the solvents for the study ofmass transport in Poly(Ethylene Terephthalate)(PET). Based on Harmon's modelfor Case I(Fickian),Case II(swelling) and anomalous transport,the data of mass uptake were analyzed. Pure Case I or Case II behavior did not appear in the both PET-solvents system and is affected by the atmosphere and preheatingmedium. The mass transport in PET is accompanied by a large-scale structural rearrangement,which leads to the induced crystallization of the original amorphous state. Solvent-induced crystallization was confirmed by optical microscopy (OM),X-ray diffraction (XRD),and Differential Scanning Calorimeter(DSC),which is quite different from the thermal crystallization. The density of specimen was measured by the Archimedes' principle,which can be used to estimate the weight percent of crystallites in the sample. The density ofspecimen annealed in air was approximately the same as that annealed in vacuum. The equation of Gibbs-Thomson is empolyed to explain the relationshipof crystal-thickness and melting points obtained by DSC.
Appears in Collections:材料科學與工程學系



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