本研究分析同步輻射小角度X-ray散射(SAXS)、廣角度X-ray繞射(WAXD)儀器與傅立葉紅外線光譜儀(FTIR)鑑定聚乙烯醇電紡絲順向纖維在逐步升溫回火時結構變化。WAXD分析中，以cake average 轉出不同方位角方向上繞射強度分布，並將其分峰，解析amorphous結構。以數值法積分 WAXD 2-D 圖案，並藉difference分析探討逐步升溫回火過程晶體變化，計算結晶度與晶體排列順向度。分析SAXS 2-D圖案之子午線散射強度分布、以Porod law與Debye-Bueche law修正散射強度，並計算lamella結構之特徵長度與lamella排列順向度。以逐步升溫FTIR探討結構變化、計算結晶度，偏極化FTIR圖譜分析與晶體分子鍊順向度，歸納WAXD、SAXS與FTIR在結晶度與順向度數據、比較分析結果差異。

In this study, the polyvinyl alcohol electrospun nanofibers were characterized by small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and insitu Fourier-transform infrared spectroscopy (in-situ FTIR). In WAXD analysis, the diffraction intensity distribution in different azimuth directions is transferred by cake average, and the peaks are divided to analyze the amorphous structure. Integrate the WAXD 2-D pattern by numerical method, and use the difference analysis to discuss the changes of crystalline structure during the step-wise annealing, then calculate the degree of crystallinity and crystalline orientation. We analyzed the meridional intensity profile of the SAXS 2-D pattern, modified the scattering intensity by Porod law and Debye-Bueche law, and calculated the characteristic length of the lamellae structure and the lamellae orientation. In-situ FTIR is used to discuss structural changes, calculate crystallinity, polarized FTIR spectrum analysis and crystal molecular chain alignment, summarize WAXD, SAXS and FTIR crystallinity and alignment data, and compare and analyze the differences.

[1] 蔡承瑋, “以電紡絲法製備聚乙烯醇纖維及其微結構鑑定”, 國立成功大學碩士論文 (2011).
[2] C. W. Bunn, “Crystal structure of polyvinyl alcohol.” Nature, 161, 929, (1948).
[3] J. D. Cho, W. S. Lyoo, S. N. Chvalun, J. Blackwell, “X-ray analysis and molecular modeling of poly(vinyl alcohol)s with different stereoregularities.” Macromolecules, 32, 6236 (1999).
[4] C. M. Hassan, N. A. Peppas, “Structure and morphology of freeze/thawed PVA hydrogels.” Macromolecules, 33, 2472 (2000).
[5] R. Endo, S. Amiya, M. Hikosaka, “Conditions for melt crystallization without thermal degradation and equilibrium melting temperature degradation and equilibrium melting temperature” Journal of Macromolecular Science, Part B, 3,793 (2003).
[6] N. A. Peppas, P. J. Hansen, “Crystallization kinetics of poly (vinyl alcohol).” Journal of applied polymer science, 27, 4787. (1982).
[7] Z. M. Huang, et. al. “A review on polymer nanofibers by electrospinning and their applications in nanocomposites” Composites science and technology, 63, 2223 (2003).
[8] P. D. Hong, K. Miyasaka, “Structure of the amorphous phase in highly drawn poly(vinyl alcohol) fibres” Polymer, 35, 1369 (1994)
[9] T. Miyazaki, Y. Takeda, A. Hoshiko, K. Shimokita, D. Ogomi, “Evaluation of oriented amorphous regions in polymer films during uniaxial deformation; structural characterization of a poly(vinyl alcohol) film during stretching in boric acid aqueous solutions” Polymer Engineering and Science, 55, 513 (2015)
[10] T. Yano, et. al., “Orientation of poly(vinyl alcohol) nanofiber and crystallites in non-woven electrospun nanofiber mats under uniaxial stretching” Polymer, 53, 4702 (2012)
[11] R. Ricciardi, et. al., “X-ray diffraction analysis of poly(vinyl alcohol) hydrogels, obtained by freezing and thawing techniques” Macromolecules, 37, 1921 (2004)
[12] S. K. Mallapragada, N. A. Peppas, “Dissolution mechanism of semicrystalline poly(vinyl alcohol) in water”, Journal of Polymer Science Part B: Polymer Physics,34, 1339 (1996).
[13] O. N. Tretinnikov, S. A. Zagorskaya, “Determination of the degree of crystallinity of poly(vinyl alcohol) by FTIR spectroscopy” Journal of Applied Spectroscopy. 79, 521 (2012).
[14] P. S. Thomas, J. P. Guerbois, G. F. Russell, B. J. Briscoe, “FTIR study of the thermal degradation of poly(vinyl alcohol)” Journal of Thermal Analysis and Calorimetry, 883, 181 (2008)
[15] S. Morita, H. Shinzawa, I. Noda, Y. Ozaki, “Perturbation-correlation moving-window 2D correlation analysis of temperature-dependent infrared spectra of a poly(vinyl alcohol) film” Journal of Molecular Structure, 883, 181 (2008)
[16] S. R. Samanta, W. W. Lanier, R. W. Miller, M. E. Gibson, “Fiber structure study by polarized infrared attenuated total reflection ppectroscopy: orientation development of Nylon 66 at various ppinning speeds.” Applied Spectroscopy, 44, 1137 (1990)
[17] B. J. Holland, J. N. Hay, “The thermal degradation of poly(vinyl alcohol).” Polymer, 42, 6775. (2001)
[18] C. Y. Liang, F. G. Pearson. “Approximate normal vibrations of crystalline polyvinyl alcohol.” Journal of Polymer Science, 35, 128, 303 (1959).
[19] A. Bozdoğan, B. Aksakal, O. Yargi. “Film formation and mechanical properties of an opaque titanium dioxide and transparent polyvinyl alcohol composite films.” Polymer Composites, 41, 3, 939 (2020).
[20] Y. Okada, et al. “Whitening of polyvinyl alcohol used as restoration material for Shohekiga.” Polymer journal, 43, 1, 74 (2011).