caa a22 4500 475764110 CHVBK 20180406123559.0 cr unu---uuuuu 170329e20001201xx s 000 0 eng 10.1007/s003960000387 doi (NATIONALLICENCE)springer-10.1007/s003960000387 High molecular weight syndiotacticity-rich poly(vinyl alcohol) gel in aging process [Elektronische Daten] [J. H. Choi, W. S. Lyoo, H. D. Ghim, S.-W. Ko] The properties of the aged gels of high molecular weight syndiotacticity-rich poly(vinyl alcohol)s (HMW S-PVAs) with different syndiotactic diad (s-diad) contents were investigated. HMW S-PVA gels with s-diad content of 61.5% and 58.2% showed the rapid increases of the syneresis and the turbidity from the early stage of aging time, which is ascribable to the phase separation, while that with s-diad content of 55.7% did not. From the morphological study, it was confirmed that the phase separation in HMW S-PVA gel with s-diad content of 61.5% occurred without the liquid-liquid phase separation in sol state, whereas both the liquid-liquid phase separation in sol state and the subsequent phase separation in gel state occurred in the case of HMW S-PVA gel with s-diad content of 58.2%. On the other hand, HMW S-PVA gel with s-diad content of 55.7% showed neither the liquid-liquid phase separation in sol state nor the phase separation in gel state in the long period of time. It was also confirmed from wide angle X-ray diffractogram that the crystallization was accompanied by the phase separation in gel state in the aging process of PVA gel. However, the crystallization was hindered by the fast network formation at the initial stage of time. Later the syndiotacticity promoted the crystallization. The tensile modulus of HMW S-PVA gel with higher syndiotacticity increased more significantly with time. Springer-Verlag Berlin Heidelberg, 2000 Key words Aging nationallicence Poly(vinyl alcohol) nationallicence Gel nationallicence Syndiotacticity nationallicence High molecular weight nationallicence Choi J. H. Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut Lyoo W. S. School of Textiles, Yeungnam University Kyongsan 712-749, Korea, KR aut Ghim H. D. Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut Ko S.-W Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut https://doi.org/10.1007/s003960000387 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s003960000387 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Choi J. H. Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut NATIONALLICENCE 700 1- Lyoo W. S. School of Textiles, Yeungnam University Kyongsan 712-749, Korea, KR aut NATIONALLICENCE 700 1- Ghim H. D. Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut NATIONALLICENCE 700 1- Ko S.-W Department of Fiber and Polymer Science College of Engineering Seoul National University Seoul 151-742, Korea e-mail: sohkwonk@gong.snu.ac.kr, KR aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer