ツクシ　イタル   TSUKUSHI Itaru   筑紫　格    所属   千葉工業大学  工学部 教育センター（工学部）    千葉工業大学  工学研究科 工学専攻    千葉工業大学  工学研究科 応用化学専攻    職種   教授
言語種別	英語
発行・発表の年月	2020/06/05
形態種別	学術雑誌
査読	査読あり
標題	Excess heat capacity for low-molecular-weight amorphous polystyrene below the glass-transition temperature: influence of end groups
執筆形態	共著
掲載誌名	Polymer Journal
掲載区分	国外
出版社・発行元	The Society of Polymer science, Japan
巻・号・頁	52(6),pp.575-580
総ページ数	6
担当区分	最終著者,責任著者
著者・共著者	Marika Yokota, Eri Nishiyama, Jun Fujimura, Itaru Tsukushi
概要	In this work, we analyze the absolute heat capacity below the glass-transition temperature Tg for two types of amorphous polystyrene with differing low-molecular weights. Both amorphous polystyrenes have excess heat capacities that cannot be reproduced by skeletal and group vibrations from 70 K to Tg, which differs from the results for amorphous polystyrene with large molecular weights. The excess heat capacity is analyzed using the Schottky model. The ratio of the degrees of freedom of the Schottky model NSC for PS-A300 and PS-A500 (NSC,PS-A300/NSC,PS-A500) is 1.6, which reflects the ratio of the end groups per molecule ((i.e., the number of monomer units of PS-A500/the number of monomer units of PS-A300 = 5/3) = 1.7), and the resulting excitation energy (=31 meV) is consistent with that determined using inelastic neutron scattering (=30 meV).