アキヤマ　ヨシカツ   Akiyama Yoshikatsu   秋山　義勝    所属   医学研究科 医学研究科 (医学部医学科をご参照ください)    職種   講師
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Alteration of the upper critical solution temperature (UCST) behavior of the nonionic polymer poly(N-acryloyl-nipecotamide) by its terminal group
掲載誌名	正式名：European Polymer Journal 略　 称：Eur. Polym. ISSNコード：0014-3057/1873-1945
掲載区分	国外
出版社	Elsevier
巻・号・頁	220(15),pp.113454
総ページ数	9
著者・共著者	AKIYAMA Yoshikatsu†, OSAWA Shigehito, MASAMUNE Ken, MURAGAKI Yoshihiro
担当区分	筆頭著者,責任著者
発行年月	2024/09/11
概要	The effect of terminal groups on the cloud points (CPs) of non-ionic polymers with upper critical solution temperature (UCST) has been a topic of interest, but detailed studies are limited. This research examines how the terminal groups of poly(N-acryloyl-nipecotamide)s (PNANAms) influence their CPs in aqueous solutions. PNANAms with different molecular weights (Mn) ranging from 4,100 to 34,300 and varied terminal groups were synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization. The temperature-dependent optical transmittance measurements revealed that CPs were influenced by not only Mn and polymer concentration but also the terminal groups. PNANAms with low Mn (Mn ≥ 7,500) and hydrophobic (dodecyl) terminal groups exhibited poor solubility, while those with moderate Mn (Mn ≤ 10,200) and hydrophilic (maleimide or carboxylic) terminal groups dissolved easily in water. PNANAms with high Mn (Mn = 34,300), however, showed poor solubility, likely due to strong inter- and intramolecular hydrogen bonding, which increased their CP. PNANAms with low Mn (Mn = 4,100) and hydrophobic terminals, as well as those with moderate Mn (13,200 ≤ Mn ≤ 18,200) and hydrophilic terminals, exhibited CPs in solution. The CP of PNANAms with carboxylic terminals was affected by pH due to the deprotonation of these groups. Phase-contrast microscopy was used to directly observe polymeric aggregates, and temperature-dependent aggregation and dispersion were explained by hydrogen bonding among PNANAm chains. Finally, a cell viability assay was performed to explore the potential of PNANAms in biomaterials and regenerative medicine applications.
DOI	10.1016/j.eurpolymj.2024.113454