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標題: 高分子PET之質傳及結構特性
Mass transport and structural characteristics of poly(ethylene terephthalate)
作者: 陳哲禎
Chen, Che Chen
關鍵字: PET
mass transport
出版社: 材料工程學研究所
摘要: 有機溶劑如丙酮在聚對苯二甲酸乙烯酯PET(poly ethylene terephthalate)中有質傳 現象,在此以Fickian與swelling,亦即所謂的 case I與case II的機制來研究質傳行為, 並且求出擴散速度v及擴散係 數D及其活化能.由於此種模式已成功的解釋了非晶形高分 子材料中的質 傳現象,所以本研究工作將著重於半結晶(semi-crystalline)高分子. 有 機溶劑在PET中的質傳與在非晶形高分子材料如PMMA中的情況是不一樣的, 在PET中是 伴隨著大規模的結構重組,導致在原來的非晶形狀態部份轉變 至晶體結構,即所謂的溶劑 誘發(solvent-induced)結晶.由SEM觀察到不 同實驗條件下的試片有不同的斷面結搆,由 X-ray繞射得知,經丙酮等處 理過的PET會有結晶現象,其X-ray繞射面與140C熱處理結晶 的繞射面一 致.由DSC掃瞄圖顯示出丙酮處理過的PET之結晶溫度Tc消失,玻璃轉移溫度 Tg 亦明顯下降.
Organic solvents like acetone etc. can penetrate into poly( ethyleneterephthalate). The model of case I(Fickian) and case II(swelling) is employedto study mass transport and to estimate the diffusion coefficient D,volicity v.This model can be used to explained the mass transport phenomena in amorphouspolymer . The incentive of our work is to see how this model works in the semi-crystalline polymer. The mass transport in poly(ethylene terephthalate)is different from that in PMMA. It is accompanied by a large-scale structuralrearrangement in the poly(ethylene terephthalate),which leads to the induced crystallization of the original amorphous state. Thiis is the so-called "solvent- induced crystallization". We observe the morphology of sample under different experimental conditions by using scanning electron microscope(SEM).Acetone-induced crystallization can be confirmed from X-ray diffraction,and it''s structure is about the same as that abtained by being heat-treated at 140 C . The DSC thermograms of acetone-treated poly(ethylene terephthalate)shows that the crystallization peak disappears and glass transition temperature(Tg) decreases.
Appears in Collections:材料科學與工程學系



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