Miscibility, Phase Morphology and Intermolecular Interactions of Natural Polyphenol/Biodegradable Polyester and Natural Polyphenol/Polyester Blends

• Main Authors: Ming-Chien Wu, 吳明謙
• Other Authors: Li-Ting Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/66967646214888059432

碩士 === 逢甲大學 === 材料科學與工程學系 === 101 === Miscibility of natural polyphenol/biodegradable polyester and natural polyphenol/poly (vinyl acetate) (PVAc) blends were studied in this research. Phase morphology, thermal behavior and interactions of tannic acid/poly(butylene adipate-co-butylene terephthalate) (TA/P(BA-co-BT)), catechin/P(BA-co-BT) and catechin/PVAc blends were examined. Observations of optical microscopy (OM) and scanning electron microscope (SEM) demonstrate the TA/P(BA-co-BT) blends are with homogeneous morphology without phase separation. By differential scanning calorimeter (DSC) detection, a single and composition-dependent Tg was revealed for each of the compositions in the blends, inferring the blends are miscible through all compositions. Tg-composition relationship was also studied, and a proper description by Kwei equation was shown with fitting parameters as k=0.4 and q=80 for TA/P(BA-co-BT) blends. Fourier-transform infrared spectroscopy (FTIR) results indicate the hydrogen bonding interactions are present in the blends. Vanishing for the absorbance of TA self-associated hydroxyl groups, low-frequency shift of TA phenolic-stretching band and a spectral change of carbonyl-stretching band in the IR spectrum with varying the compositions can prove that the hydrogen bonding are formed between TA and P(BA-co-BT), which could be suggested as the main factor for resulting in the miscibility in the blends. In catechin/P(BA-co-BT) blends, miscible state and the hydrogen bonding interactions can also be found. OM and SEM observations reveal homogeneous phase morphology for the blends. DSC results show the miscible feature for the blends as the single composition-dependent Tg which can be properly fitted by Kwei equation (k=0.4 and q=180). IR spectrum display the high-frequency shit of catechin hydroxyl-stretching band and the appearance of hydrogen-bonded absorbance for P(BA-co-BT) carbonyl-stretching band, inferring the formation of hydrogen bonding between catechin and P(BA-co-BT). In addition, catechin/PVAc blends can also be presented as the miscible blends with forming the intermolecular hydrogen bonding interactions. Homogeneous phase morphology without phase separation can be resolved by OM and SEM. The single and composition-dependent Tg with fitting by Kwei equation (k=0.3 and q=80) can also be shown by DSC results, indicating the catechin/PVAc blends are miscible. IR results demonstrate the high-frequency shit of catechin hydroxyl-stretching band and the appearance of hydrogen-bonded absorbance for PVAc carbonyl-stretching band. The hydrogen bonding interactions can be proved to exist between catechin and PVAc. Furthermore, it might also mainly contribute the miscibility in the blends.