高分子摻合體之液-液相分離與結晶程序相互競爭形態控制之研究

Study on the competivity between crystallization and liquid-liquid

梁廣恒(kung-Heng Liang)

指導教授 ： 黃振球

元智大學/工程學院/化學工程與材料科學學系/碩士(1997年)

摘要

高分子摻合體之液-液相分離與結晶程序
相互競爭形態控制之研究
學生:梁廣恆 指導教授:黃振球
元智大學化學工程研究所
摘要
PET與PEI的摻合系統在熔點之下是液-液相分離與結晶行為同
時進行且處於相互競爭的形態。由先前的研究知液-液相分離所產生
連結domain的是由於spinodal decomposition動力學機構所造成，而
domain並被鎖在PET的晶體內部。由於相分離的形態是由結晶動力
學與spinodal decomposition所所決定，因此本研究在討論PEI分子量
對於此一摻合體的結晶與形態構造的影響。結晶動力學是藉由小角光
散射(SALS)與示差掃描熱卡計(DSC)做分析，利用光學顯微鏡來觀察
液-液相分離domain的形態。我們發現測量出液-液相分離domain的
實際長度隨著摻合體PEI分子量的上升有降低的趨勢，而晶體成長速
率則相反。因此在domain被晶體鎖住以前，含有低分子量PEI的摻
合體有較多的時間coarsening。因此我們認為spinodal decomposition
對domain size的影響較晶體成長速率來的大。

關鍵字:液-液相分離；spinodal decomposition；domain

關鍵字

液-液相分離 ； spinodal decomposition ； domain

並列摘要

Abstract
Poly(ethylene terephthalate)(PET)/poly(ether imide)(PEI) blends
exhibit competitive crystallization and liquid-liquid phase separation
below the melting point. It was found in the previous study that the
modulated (or interconnected) domains created by spinodal
decomposition can be locked in by the crystallization of PET. As the
phased-separated morphology is governed by the competition of the two
processes, the kinetics of crystallization and spinodal decomposition are
expected to play decisive roles in the morphological formation in this
binary system. In this study, we investigate the effect of the molecular
weight of PEI on the crystallization behavior and morphology of
PET/PEI blends. The crystallization kinetics of the blend are
characterized by polarized small-angle light scattering(SALS) and DSC.
The morphologies of the blends corresponding to different PEI
molecular weight are observed by optical microscopy. The results
indicate that the crystallization kinetics of PET/PEI blends is depressed
by increasing the molecular weight of PEI. The wavelength of the
modulated domain which characterized the phase-separated domain size
decreases with increasing PEI molecular weight. The modulated domain
in blends with lower PEI MW appear to have more time to undergo
coarsening before they are locked by the crystallization process. The
observed molecular weight effect is disscussed in light of the respective
effect of molecular weight on the kinetics of crystallization and spinodal
decomposition.

並列關鍵字

liquid-liquid phase separation ； spinodal decomposition ； domain

參考文獻

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