本研究利用偏光顯微鏡(polarized-light optical microscopy, POM)、電子顯微鏡(scanning electron microscopy, SEM)及廣角度X光繞射儀 (microbeam wide-angle X-ray diffraction, WAXD)探討生物可分解高分子聚己二酸丁二醇酯(poly(1,4-butylene adipate), PBA)與聚乙二醇(poly(ethylene oxide), PEO)以熔融結晶方式形成之環帶狀球晶及樹枝狀球晶形貌，並觀察其生長機制。
將PBA與PEO進行混摻，初步以POM觀察，當PEO比例增加時，會使PBA形成環帶狀球晶的結晶溫度區間縮減，在同結晶溫度下，PEO含量越高，使球晶越容易形成樹枝狀球晶，隨著結晶溫度越高，樹枝狀球晶分枝變的明顯。後續以甲醇當作蝕刻劑，將能鬆弛PBA內部晶板的PEO移除，進一步以SEM觀察PBA上表面及內部晶板排列。第一部分首先以PBA/PEO (90/10) Tc = 30 oC之組成觀察上表面晶板的排列方向，並用偏光顯微鏡在放大倍率約為實際樣品的1000倍下，觀察到消光環帶對應到上表面晶板排列的關係，並進一步結合內部晶板建立出PBA完整的環帶狀球晶生長機制，發現內部垂直生長的晶板會以twist後重新分枝成平行晶板的方式生長，最後，再比較不同組成下其內部晶板排列之變化。第二部分則是在PBA/PEO (25/75)系統中，在不同結晶溫度下，比較環帶狀球晶與樹枝狀球晶生長機制，歸納出在樹枝狀球晶中，直立的晶板會偏折形成平行於基材的晶板，和環帶狀球晶中的ridge處晶板轉折形成valley處的晶板，有著相似的機制。

In this study, polarized optical microscopy (POM)、scanning electron microscopy (SEM) and microbeam wide-angle X-ray diffraction (WAXD) were used to investigate the growth mechanism of ring-banded spherulites in poly (1,4-butylene adipate) (PBA) / poly(ethylene oxide) (PEO) blend systems. It is found that when the content of PEO increases, the crystallization temperature range where PBA can form ring-banded spherulites decreases. The lamellar arrangement of ring-banded spherulite at 30 oC in PBA/PEO blend system, was probed by using scanning electron microscopy (SEM) to observe top surface and interior structures. Moreover, the correlation between lamellar assembly and periodic extinction/birefringence bands is connected by using POM and SEM. It is found that the inner lamellae are arranged perpendicularly to the substrate under the ridge region and they twist 90o to branch out new lamellae to form the parallel lamellae under the valley region. Moreover, the irregular and different orientation of twisting and re-branching lamellae lead to optical extinction band, and the regular arrangement of lamellae lead to optical birefringence band in POM. Finally, in the PBA/PEO (25/75) system, the growth mechanism of ring-banded spherulites and dendritic spherulites is compared, and it is deduced that the edge-on lamellae in dendritic spherulites bend to form flat-on lamellae. The mechanism of the lamellar arrangement at ridge and valley on the top surface of ring-banded spherulites is similar to the growth mechanism of dendritic spherulites.

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