Postfunctionalization of poly(vinyl alcohol) (PVA) was performed in supercritical carbon dioxide (sc-CO2) for the selective functionalization of the amorphous region. The crystalline region was retained in the amorphous-selective acetylated PVA. The oriented structure of crystallites of the drawn PVA was maintained even after acetylation in sc-CO2. Moisture adsorption behaviors affected the crystalline structure of PVA acetylated in sc-CO2. The PVA acetylated in sc-CO2 included a larger number of water molecules under humid conditions, but the increase in thickness after water adsorption was smaller than that of randomly acetylated PVA.
- Takuya Matsumoto
- Miyabi Yorifuji
- Takashi Nishino
