Exploration of tertiary aminosquaramide bifunctional organocatalyst in controlled/living ring-opening polymerization of l-lactide

Journal of Polymer Science Part A: Polymer ChemistryVolume 55, Issue 15 p. 2483-2493 Article Exploration of tertiary aminosquaramide bifunctional organocatalyst in controlled/living ring-opening polymerization of l-lactide Ali Rostami, Corresponding Author Ali Rostami a_rostami@sbu.ac.ir orcid.org/0000-0003-3250-6869 Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranCorrespondence to: A. Rostami (E-mail: a_rostami@sbu.ac.ir)Search for more papers by this authorElahe Sadeh, Elahe Sadeh Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranSearch for more papers by this authorShaghayegh Ahmadi, Shaghayegh Ahmadi Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranSearch for more papers by this author Ali Rostami, Corresponding Author Ali Rostami a_rostami@sbu.ac.ir orcid.org/0000-0003-3250-6869 Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranCorrespondence to: A. Rostami (E-mail: a_rostami@sbu.ac.ir)Search for more papers by this authorElahe Sadeh, Elahe Sadeh Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranSearch for more papers by this authorShaghayegh Ahmadi, Shaghayegh Ahmadi Department of Polymer and Material Chemistry, Shahid Beheshti University, Tehran, 19839–4716 I. R. IranSearch for more papers by this author First published: 07 May 2017 https://doi.org/10.1002/pola.28641Citations: 12Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat ABSTRACT A series of tertiary aminosquaramides as bifunctional organocatalysts in the ring-opening polymerization (ROP) of l-lactide (l-LA) were developed, allowing the activation of both the l-LA monomer and the alcohol group of the initiator/propagating species. Further, the impact of tertiary nitrogen substituents on catalytic activity in ROP of l-LA was explored. The tertiary aminosquaramide— an air-stable and moisture-stable catalyst—exhibited superior activity in contest with thiourea counterpart when both were equipped with a similar tertiary amine group. Kinetic and chain-extension experiments indicated that the formed poly(l-LA) is featured with narrow polydispersity and high end-group fidelity, hallmarks of a living polymerization process. The initiator efficiency was further executed at ease by preparation of an ABA triblock copolymer poly (l-LA)-b-poly (ethylene glycol)-b-poly (l-LA) in the presence of a dual-headed PEG macroinitiator. 1H NMR titration experiments suggested a bifunctional catalytic mechanism, wherein both the l-LA monomer and the propagating hydroxyl group were activated en route to polymerization. The 1H NMR, SEC, and MALDI-TOF MS measurements validated the quantitative incorporation of the initiator in the polymeric chains and enchainment over competitive trans-esterification reaction. Overall, the structure-activity relationships were surveyed to uncover aminosquaramide as a new bifunctional dual hydrogen-bond donor catalyst for living ROP of l-LA. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2483–2493 Citing Literature Supporting Information Additional Supporting Information may be found in the online version of this article. Filename Description pola28641-sup-0001-suppinfo.pdf3 MB Supporting Information Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume55, Issue15August 1, 2017Pages 2483-2493 RelatedInformation