Synthesis and characterization of polyrotaxanes comprising 伪-cyclodextrins and poly(蔚-caprolactone) end-capped with poly(N-isopropylacrylamide)s

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• 作者：Pei-jing Wang ; Jin Wang ; Lin Ye ; Ai-ying Zhang ; Zeng-guo Feng ; ^{sainfeng@bit.edu.cn}
• 关键词：伪-cyclodextrin ; Poly(蔚-caprolactone) ; Polyrotaxane
• 刊名：Polymer
• 出版年：2012
• 期刊代码：83_00323861
• 类别：ms
• 出版时间：25 May, 2012
• 卷：53
• 期：12
• 页码：2361-2368
• 文件大小：894 K

摘要

Biodegradable polyrotaxane (PR)-based triblock copolymers were synthesized via the atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAm) initiated with polypseudorotaxanes (PPRs) consisting of a distal 2-bromopropiomyl bromide end-capping poly(蔚-caprolactone) (Br-PCL-Br) and a varying amount of 伪-cyclodextrins (伪-CDs) in the presence of Cu(I)Br/PMDETA at 25聽掳C in aqueous solution. The copolymers were featured by relatively higher yields from 46.0%to 82.8%as compared with previous reports. Their structure was characterized in detail by using ¹H NMR, ¹³C CP/MAS NMR, GPC,聽WXRD, DSC and TGA analyses. When a feed molar ratio of NIPAAm to Br-PCL-Br was changed from 50 to 200, the degree of polymerization of PNIPAAm blocks attached to two ends of PPRs was in a range of 158-500. About one third of the added 伪-CDs were still entrapped on the central PCL chain after the ATRP process. Attaching PNIPAAm rendered the copolymers soluble in aqueous solution showing the thermo-responsibility as evidenced by turbidity measurements.