本研究目的是進行體內可吸收性高分子複合材料的改質，以期更適於口腔顎 面外科、整形外科及骨科之應用。以二氯甲烷為共同的溶劑，分別溶解基質 - 聚左乳酸 (PLLA) 、第二添加物 - 聚左右乳酸 (PDLLA) 或聚己內酯 (PCL) 及 界面活性劑 - 聚乙烯氧化聚合物 - 聚丙烯氧化聚合物 (PEOPPO) ，將此三種成 分進行不同比例的摻合，其中 PLLA 和 PDLLA 的重量百分比為 100/0 、 80/2 0 、 60/40 、 50/50 、 40/60 、 20/80 及 0/100 。實驗上利用熱重分析儀、微差 掃描式熱分析儀 (DSC) 、紅外線光譜測定儀、膠體滲透層析儀、掃描式電子 顯微鏡及材料機械性質測定儀來量測結晶熔點、玻璃轉化溫度、相的表現及 機械特性。由 DSC 結果發現，沒有添加界面劑之 PLLA/PDLLA 摻合物有兩 個玻璃轉化溫度的趨勢，而在添加界面劑後的摻合物其玻璃轉化溫度會隨著 PLLA 成分的減少而降低，且呈線性的轉移。在機械性質的比較上，未添加 界面活性劑前 PLLA/PDLLA 摻合物最佳強度的摻合比例為 40/60 ，而適當的 界面活性劑濃度為 2% ，此時 PLLA/PDLLA 摻合物最佳強度的摻合比例為 50 /50 。 PLLA 添加 PCL 後，伸長量 (elongation) 增加最多，但強度變弱。觀察 摻合物斷面型態，發現硬而韌的材料具有絲絮狀不光滑之斷面。綜合本研究 的結果發現，以摻合的方式加入界面活性劑進行高分子材料的改質可找到一 最佳的組成分且具較優的機械性質。
生物可降解性牙用 / 骨用聚乳酸高分子摻合物的製備
與鑑定
The purpose of this study is to improve the properties of bioresorbable materials for particular applications in dental and orthopedic surgery. Blends of biodegradable poly-L-lactic acid (PL LA), poly- DL-lactic acid (PDLLA) or polycaprolactone (PCL) , and a third component, the su rfactant PEO-PPO, were prepared by blending these three polymers at various ratios using dic hloromethane as a solvent. The weight percentages of PLLA/PDLLA (or PCL) blends were 10 0/0, 80/20, 60/40, 50/50, 40/60, 20/80 and 0/100, respectively. Physical and morphological pr operties such as crystalline melting point, glass transition point, phase behaviors, degradation behavior and mechanical properties were characterized by thermogravimetric analysis, differe ntial scanning calorimetry, infrared spectroscopy, gel permeation chromatography, scanning el ectron microscopy and dynamic mechanical analysis. DSC data indicate that PLLA/PDLLA bl ends without PEOPPO have two Tgs. With the addition of PEOPPO, there is a linear shifting of Tg as a function of composition showing a lesser percentage of PLLA, and a lower glass tra nsition temperature indicating better miscibility has been achieved. DMA data show the best c omposition of PLLA/PDLLA blends without PEOPPO is 40/60, and the best concentration of PEOPPO is 2%. The 50/50 PLLA/PDLLA/2%PEOPPO blend has better mechanical propertie s. Elongation of PLLA increases while adding PCL, but the strength decreases at the same tim e. SEM observation shows that harder and tougher materials have rougher fracture surface mor phology.
Preparation and Characterization of Biodegradable PLA Polymeric Blends for Dental and Orthopedic
application
