聚乙二醇末端基對聚乳酸與聚乙二醇摻合物薄膜之影響

Abstract

本論文旨在研究聚乳酸(PLLA)摻合不同末端基之聚乙二醇(PEG)以濕式法(wet casting method)製成薄膜，以瞭解不同末端基之聚乙二醇對聚乳酸之影響。採用的四成分系統為：聚乳酸/聚乙二醇-1,4二氧陸圜-正庚烷；聚乳酸與聚乙二醇為互溶性高分子，因此可視為一相，而溶劑和非溶劑則分別為1,4二氧陸圜與正庚烷。藉由實驗相圖的製備，可以得到改變聚乙二醇末端基造成液-液及固-液相分離的成分位置變化，且利用SEM則可觀察不同末端基之聚乙二醇及鑄膜液的濃度對結構造成的影響。PLLA/PEG(2CH3)、(1OH-1CH3)、(2OH)之薄膜結構會隨著鑄膜液的濃度變化；然而，PLLA/PEG(2NH2)之薄膜結構型態卻不若其他三者。此外，PLLA/PEG(2NH2)溶液黏度由Ubbelohde測量發現其黏度跟其他三者相較極低。由上，可更進ㄧ步了解聚乙二醇末端基如何影響聚乳酸/聚乙二醇薄膜結構。

The study focuses on the effect of PEG with different end groups blending PLLA to prepare membranes by wet casting method. In this work, owning to the miscibility of two polymers, PLLA and PEG were thought as one phase, 1,4-dioxane was the solvent and n-Heptane was the non-solvent. Via the phase diagram, it was realized how liquid-liquid de-mixing and solid-liquid de-mixing varied with the end groups of PEG. The structure of membranes prepared with different end groups of PEG and the concentration of casting solutions can be observed clearly by SEM. The structures of PLLA/PEG(2CH3), (1OH-1CH3), and(2OH) were observed varying with the concentration of casting solutions; nevertheless, the structures of PLLA/PEG(2NH2) were found dissimilar with others. Besides, the viscosity of PLLA/PEG(2NH2) casting solution measured by the Ubbelohde viscosmeter was extreme lower than others. Through the above work, it was found how PEG end groups affected the structures of PLLA/PEG membranes.