| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 102 === Poly(butylene adipate) (PBA), a biodegradable linear aliphatic polyester, can be potentially applied as the biomedical and eco-friendly materials. In this study, the Mg-Al layered double hydroxides (LDH) prepared using one-step coprecipitation method were successfully synthesized by intercalating the oleate or sorbitol and oleate into the interlayer spacing of LDH (assigned as OLDH and SOLDH).Wide-angle X-ray diffraction data showed the interlayer spacing increased from 0.83nm of LDH into 3.4nm and 5.88nm of OLDH and SOLDH with the addition of oleate and the mixture of sorbitol/oleate. The surface property of LDH was changed from hydrophilic to hydrophobic characteristic. The PBA/OLDH and PBA/SOLDH nanocomposites were prepared via a solution mixing process. The structure and morphology of nanocomposites investigated using X-ray diffraction and TEM micrographs showed the OLDH and SOLDH were all randomly dispersed into the PBA matrix.The structure of nanocomposite is partial exfoliated and intercalated comformation. Effect of OLDH and SOLDH on the crystallization behavior was investigated using a differential scanning calorimetry (DSC) and polerized optical microscopy(POM).Isothermalcrystallization results of PBA/OLDH and PBA/SOLDH nanocomposites showed that the addition of OLDH and SOLDH into PBA induced more steric hindrance of the diffusion of PBA, reducing the transportation ability of polymer chains during crystallization, thus decreasing the crystallization rate and increasing chain folding surface energy. The thermal properties of nanocomposites observed by TGA. Showed that the T10d was increasedto 7.3℃and 49℃ by adding 0.1wt % OLDH and SOLDH. For theenzymatic degradation experiments, the film soaked in a solution containing Lipase from Pseudomonas fluorescens was observed by measuring the percentage of weight loss. Compared to different OLDH and SOLDH content of film, the weight loss was decreased with the same degradation time, illustrating that the degradation rate was decreased by increasing content of OLDH and SOLDH. This result is presumably due to the presence of OLDH and SOLDH to induce the closely compact in amorphous region of PBA.By GPC and XRD analysis, the crystallinity and molecular weight of PBA / OLDH and PBA / SOLDH composites did not significantly change, which can be predicted that the degradation mechanism for hydrolysis of exonuclease.
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