PHBHHx/PDLLA 摻合電紡膜之鑑定與降解行為

Characterization and Degradation Behaviors of PHBHHx/PDLLA Blended Electrospun Membranes

陳鉑雅(Po-Ya Chen)

指導教授 ： 孫一明

元智大學/工程學院/化學工程與材料科學學系/碩士(2008年)

https://doi.org/10.6838/YZU.2008.00194

摘要

本研究將聚(3-羥基丁酸酯-共-3-羥基己酸酯) (PHBHHx) 與聚乳酸 (PDLLA)以不同比例摻合，探討製備成電紡絲膜之熱性質與結晶行為之關係，以及水降解機制的差異，並探討不同摻合比例與纖維排列方式對其機械性質的影響。
PHBHHx與PDLLA摻合系統具有各自的玻璃轉移溫度，且PHBHHx熔點不受另一物質的加入而改變，判斷此為不互混的摻合系統，更可由WAXD測得之晶粒大小與SAXS所計算出長週期、結晶層厚度研判PDLLA的添加不影響PHBHHx結晶的生成，故摻合膜之PHBHHx含量與熔融熱間具有線性加成的關係。WAXD 圖譜可觀察出摻合電紡膜僅有兩個較強的繞射峰，其繞射峰強度隨著無定形PDLLA的添加而逐漸下降。
纖維膜相較於溶鑄膜具有較佳的延展性，其機械性質決定於纖維的順向性以及膜材孔隙度多寡，透過順向性纖維膜不同方向上的拉伸，可以得知纖維本身具有又強又硬的機械強度。隨著PDLLA的添加，摻合膜之延展性提升亦逐漸變為柔軟，抗張強度及彈性模數相對下降。
由摻合膜降解之SEM圖譜觀察出PHBHHx屬於表面降解而PDLLA則屬於整體降解，在降解24週後重量損失均小於3 %，但其分子量已有明顯下降的趨勢且分子量分佈隨降解時間增加而增加。

關鍵字

聚(3-羥基丁酸酯-共-3-羥基己酸酯) ； 聚乳酸 ； 電紡 ； 摻合 ； 機械性質 ； 水解

並列摘要

Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(D, L-lactic acid) (PDLLA) in different ratios were fabricated into fibrous membranes by electrospinning processes. PHBHHx and PDLLA kept individual glass transition temperatures in the blend system and the melting point of PHBHHx didn’t shift with the added PDLLA indicated that the blend system was immiscible. The crystal size measured by WAXD and the long period estimated by SAXS were kept the same in the blends. The enthalpy of fusion and the PHBHHx content of the blends were linearly correlated. Therefore, it can be concluded that PDLLA in the blend system didn’t affect the growth of PHBHHx crystalline phase and PDLLA was excluded from PHBHHx lamella stack. The electrospun fibrous membranes of the blends only had two diffraction peaks due to the oriented chain packing in the crystalline phase in the fibers, and the intensity of those two peaks decreased as the amorphous PDLLA increased. The mechanical properties of the electrospun fibrous membranes depended on the orientation of fibers and the porosity in the membranes. The electrospun membranes had higher elongation, and the individual electrospun fibers were stronger and stiffer than the corresponding cast membranes. As the content of PDLLA increased, the electrospun fibrous membranes of the blends showed higher elongation and lower elastic modulus. The hydrolytic degradation of the electrospun fibrous blends observed by SEM indicated that the PHBHHx portion proceeded surface erosion and the PDLLA portion was characterized by bulk erosion. After 24-week degradation, the mass loss of the fibrous blends was less than 3 %. The molecular weight lowered and the PDI was raised with degradation time.

並列關鍵字

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) ； poly(D,L-lactic acid) ； blend ； electrospinning ； mechanical property ； hydrolysis

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