A method for cyclic and tadpole‐shaped polymers. Issue 8 (18th March 2015)

• Record Type: Journal Article
• Authors: Tang, Qingquan; Zhang, Ke
• Is Part Of: Polymer international. Volume 64:Issue 8(2015:Aug.)
• Page Start: 1060
• Page End: 1065
• Publication Date: 2015-03-18
• Subjects: Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1002/pi.4906
• Languages: English
• ISSNs: 0959-8103

Abstract

<abstract abstract-type="main" id="pi4906-abs-0001"> <title>Abstract</title> <p id="pi4906-para-0001">Reversible addition–fragmentation chain transfer polymerization (RAFT) was used to produce well‐defined telechelic poly(<italic>N</italic>‐isopropylacrylamide) (PNIPAM) with dibromomaleimide and dithiobenzoate groups at each end of the polymer chain by virtue of the functional RAFT agent 3, 4‐dibromo‐1‐(4‐cyano‐4‐(phenylcarbonothioylthio)pentanoic)‐2, 5‐dihydro‐1<italic>H</italic>‐pyrrole‐2, 5‐dione. Cyclic PNIPAM was then obtained using an <italic>in situ</italic> intramolecular bromomaleimide–thiol substitution reaction after NaBH₄ reduction of the dithiobenzoate end group to release a thiol group. In this ring‐closure process, another bromo substituent on the maleimide group survived, being a single reactive site for post‐functionalizing the cyclic PNIPAM by a second bromomaleimide–thiol substitution reaction. After being reacted with 2‐aminoethanethiol, the resultant amino‐functionalized cyclic PNIPAM was further demonstrated as a building block to construct a tadpole‐shaped block copolymer by coupling with linear succinimidyl ester end‐functionalized poly(ethylene oxide) based on active ester click chemistry. © 2015 Society of Chemical Industry</p> </abstract>