本研究應用偏光顯微鏡(polarized optical microscopy，POM)、微分掃描熱卡計(differential scanning calorimeter，DSC)、掃描式電子顯微鏡(scanning electron microscopy，DSC)和原子力顯微鏡(atomic force microscopy，AFM)分別探討：聚羥基丁酸酯[poly(3-hydroxybutyrate)] (PHB)與其混摻系統，以熔融結晶的方式，形成之球晶形貌、裂縫形貌與晶板排列。
在neat PHB系統中，藉由其環帶狀形貌的特徵，採用不同的熱處理條件以及分子量，使其環帶狀特徵變得更規則，以利後續研究觀察及分析；而透過高分子混摻(polymer blending)，亦可得到較規則之球晶形貌，但過程中必須考慮到高分子相容性。針對相容系統，其球晶形貌與內部晶板排列相符；反之，相分離系統，其晶板內部存在許多球狀domain，與其球晶形貌不符。為了深入研究裂縫，故藉由改變不同環境狀態來取得較完整裂縫形貌，再觀察其裂縫與球晶形貌之對應性，可以發現針對相容系統，越規則之球晶形貌，會對應到較規則之裂縫形貌；而相分離系統，其晶板內部的domain會影響到裂縫的生成，故其裂縫形貌無法對應到其球晶形貌；因此對於裂縫之研究應深入球晶內部結構，藉由SEM可以觀察到裂縫好發於兩種不同基板排列(排列方向垂直或平行於基材)之交界處，以及PHB內部晶板之不連續界面，藉此了解到裂縫與晶板排列之關係，進而推論出裂縫、球晶形貌和晶板排列三者之關聯性。

Correlations between morphologies, cracks and lamellar assembly from melt-crystallization of PHB and its blend system have been investigated. Spherulitic morphologies of neat PHB are influenced by different thermal treatment or blending other polymers. For the polymer blending, the miscibility is a most important factor that influences the properties of materials. When the PHB blend system is miscible, the spherulitic morphology would correspond with the interior lamellar arrangement. After quenching, the cracks would appear and follow the ring-banded pattern for the miscible system. However, when the PHB blend system is immiscible, the interior structure would be filled with domains. In the immiscible system, spherulites display irregular cracks due to the existence of phase-separation domains. In order to know the relationship between cracks and lamellar assembly, scanning electron microscopy (SEM), atomic-force microscopy (AFM) and polarized optical microscopy (POM) have been used. The regular spiral cracks are found at the interface between the valley and ridge, induced by the discontinuous lamellar arrangement occur. The possible mechanisms of cracks on polyesters’ spherulites have been discussed thoroughly.

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