生物可降解型水性聚胺酯之熱感應自組裝行為研究

Abstract

本研究結合三種不同的生物可降解型聚酯二元醇類做為聚胺酯材料軟鏈段組成。並以新穎的水性製程合成水性聚胺酯奈米微粒分散液。藉由動態光散射，多角度光散射，穿透式電子顯微鏡與小角度X光散射等分析方法，發現水性聚胺酯奈米微粒(WBPU NP)主要呈現堅實的圓球狀態，並且隨著軟鏈段組成的差異，呈現不同的形狀因子(shape factor)。在軟鏈段分別由80 mol%之與20mol%的組成的WBPU NP中，發現到有一特殊的熱誘導膨潤現象，且在37°C下可見明顯的相變化發生於2分鐘內，並達近450%的飽和含水率。而此自組裝的現象來自高分子鏈段間的次級作用力與軟鏈段結晶度的差異。而此具生物可降解與溫度響應特性的WBPU NPs在未來可被應用於細胞或藥物載體等智慧型可分解的高分子材料。

Waterborne polyurethane (PU) with different compositions of biodegradable oligodios as the soft segment was synthesized as nanoparticles (NPs) in this study. Using dynamic light scattering (DLS), multi-angle light scattering (MALS), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), we demonstrated that these NPs were compact spheres with different shape factors. The temperature-dependent swelling of the PU NPs in water was distinct. In particular, PU NPs with 80 mol% polycaprolactone (PCL) diol and 20 mol% poly-L-lactic acid (PLLA) diol as the soft segment had significant swelling (~450%) at 37°C. This was accompanied by a sol-gel transition observed for the NP dispersion in about two minutes. The thermally-induced swelling and self-assembly of these NPs were associated with the secondary force and degree of crystallinity, which depended on the soft segment compositions. The thermo-responsiveness of the PU NPs with mixed biodegradable oligodiols may be employed to design smart biodegradable carriers for delivery of cells or drugs near the body temperature.