류원석 이철주 박기홍 김낙중 김병철 2024-01-21T14:34:09Z 2024-01-21T14:34:09Z 2022-01-10 2000-01 0367-8369 https://pubs.kist.re.kr/handle/201004/141642 Vinyl acetate (VAc) was bulk-polymerized at 30, 40 and 50°C using a low temperature initiator, 2,2′-azobis(2,4-dimethylvaleronitrile) (ADMVN), and effects of polymerization temperature and initiator concentration were investigated in terms of polymerization behavior and molecular structures of poly(vinyl acetate) (PVAc) and corresponding poly(vinyl alcohol) (PVA) obtained by saponifying it with sodium hydroxide. Low polymerization temperature and low conversion by adopting ADMVN proved to be successful in obtaining PVA of high molecular weight. PVAc having number-average degree of polymerization (Pn) of 6,800-10,100 was obtained, whose degree of branching for acetyl group of 0.6-0.7 at 30°C, 0.8-1.1 at 40°C, and 1.0-1.9 at 50°C at conversion of below 40%. Saponifying so prepared PVAc yielded PVA having Pn of 3,100-6,200, and syndiotactic diad (S-diad) content of 51-53%. The whiteness, S-diad content, and crystal melting temperature were higher with PVA prepared from PVAc polymerized at lower temperatures. ？ 2000 OPA (Overseas Publishers Association) N.V. Published by license under the Gordon and Breach Science Publishers imprint. English Taylor & Francis Preparation and molecular structure of poly(vinyl alcohol) by low temperature bulk polymerization of vinyl acetate and saponification Article 1 International Journal of Polymeric Materials, v.46, no.1-2, pp.181 - 194 International Journal of Polymeric Materials 46 1-2 181 194 N scopus 2-s2.0-0000952942 vinyl acetate