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It is also shown that the temperature dependence of the dynamics of two structural properties of spatially extended nature, the end-to-end distance and the radius of gyration, has three distinct regions separated also at those crossover temperatures, and considering the relaxation time scales, the low-, intermediate-, and high-temperature regions are assigned to the glassy, (supercooled) rubbery, and liquid (melted) states, respectively. By examining the spectrum of the vibrational density of states in a low-frequency region, which represents the dynamics of spatially more localized nature, it is suggested that inter-basin hopping associated with main-chain C\u2013C torsions is thermally activated as a precursor (from the low-temperature side, \u03b2 relaxation) to the glass transition. A change in the hydrogen-bonding network manifested by a spectral feature of the vibrational density of states is also discussed.<\/jats:p>","DOI":"10.1063\/5.0349685","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T12:14:18Z","timestamp":1790079258000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["Changes in the structural and dynamical properties in glass transition and related processes of poly(vinyl alcohol) analyzed by molecular dynamics simulations"],"prefix":"10.1063","volume":"165","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-4276-9928","authenticated-orcid":false,"given":"Hirokazu","family":"Ohsawa","sequence":"first","affiliation":[{"name":"Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University 1 , 3-5-1 Johoku, Chuo-ku, Hamamatsu 432-8561,","place":["Japan"]},{"name":"Department of Research and Development, Aicello Corporation 2 , 45 Koshikawa, Ishimakihonmachi, Toyohashi 441-1115,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2704-2716","authenticated-orcid":false,"given":"Yukichi","family":"Kitamura","sequence":"additional","affiliation":[{"name":"Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University 3 , 3-5-1 Johoku, Chuo-ku, Hamamatsu 432-8561,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6061-9599","authenticated-orcid":false,"given":"Hajime","family":"Torii","sequence":"additional","affiliation":[{"name":"Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University 1 , 3-5-1 Johoku, Chuo-ku, Hamamatsu 432-8561,","place":["Japan"]},{"name":"Department of Applied Chemistry and Biochemical Engineering, Faculty of Engineering, Shizuoka University 3 , 3-5-1 Johoku, Chuo-ku, Hamamatsu 432-8561,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"317","published-online":{"date-parts":[[2026,9,22]]},"reference":[{"key":"2026092208141095600_c1","volume-title":"Polyvinyl Alcohol - Developments","author":"Finch","year":"1992"},{"key":"2026092208141095600_c2","first-page":"890","volume-title":"Polymer Data Handbook","author":"Mark","year":"1999"},{"key":"2026092208141095600_c3","doi-asserted-by":"crossref","first-page":"1116","DOI":"10.1093\/oso\/9780195181012.001.0001","volume-title":"Polymer Data Handbook","author":"Mark","year":"2009","edition":"2"},{"key":"2026092208141095600_c4","doi-asserted-by":"publisher","first-page":"188","DOI":"10.1080\/15685551.2020.1826124","article-title":"Effect of boric acid on poly vinyl alcohol- tannin blend and its application as water-based wood adhesive","volume":"23","year":"2020","journal-title":"Des. 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