Organocatalytic sequential ring-opening polymerization of cyclic ester/epoxide and N-sulfonyl aziridine: metal-free and easy access to block copolymers. Issue 37 (3rd September 2021)

• Record Type: Journal Article
• Authors: Huang, Huishan; Luo, Wenyi; Zhu, Linlin; Wang, Ying; Zhang, Zhen
• Is Part Of: Polymer chemistry. Volume 12:Issue 37(2021)
• Page Start: 5328
• Page End: 5335
• Publication Date: 2021-09-03
• Subjects: Polymers -- Periodicals; Macromolecules -- Periodicals; Polymerization -- Periodicals; 547.705
• DOI: 10.1039/d1py00890k
• Languages: English
• ISSNs: 1759-9954

Abstract

Abstract : Sequential ring-opening polymerization of ε-caprolactone (ε-CL)/propylene oxide (PO) and N -sulfonyl aziridine switched by tosyl isocyanate (TSI) allows the metal-free synthesis of polysulfonamide-based copolymers. Abstract : We report an organocatalytic sequential ring-opening polymerization (ROP) approach for the facile synthesis of polysulfonamide-based copolymers. Alcohols and methoxylpolyethylene glycols were initially employed as (macro)initiators for the ROP of N -sulfonyl aziridines to produce well-controlled polymers with the assistance of tosyl isocyanate. Tosyl isocyanate efficiently transformed the hydroxyl species into the tosylcarbamate anion, the initiating site for the ROP of N -sulfonyl aziridines. ROP of ε-caprolactone or propylene oxide was then performed in bulk in the presence of the phosphazene base t -Bu-P2 or t -Bu-P4, followed by end-group transformation with tosyl isocyanate and the subsequent ROP of N -sulfonyl aziridines. The synthesized poly(ε-caprolactone)- block -polysulfonamide and poly(propylene oxide)- block -polysulfonamide copolymers showed a remarkable control of molar masses and dispersities. Well-defined triblock and 3-arm star-shaped copolymers were successfully prepared from diol and triol initiators.