Telechelic block copolymer L-PPI-b-poly(epoxide-alt-PA) obtained via desulfonation of poly(o-nitrophenylsulfonyl-activated aziridines)

Abstract

Copolymers combining polyesters derived from ROCOP of epoxides and anhydrides with linear polyamines will have broad structures and improved functionalities. Herein, using o-nitrophenylsulfonyl (o-Ns)-activated alaninol as a bifunctional initiator, we present the “two-step in one pot” copolymerization of 1-(2-nitrobenzenesulfonyl) 2-methyl-aziridine (NsMAz) with epoxides (PO, BO, and GMA) and phthalic anhydride (PA) for the synthesis of telechelic block copolymers after desulfonation. Under the premise that hydroxyl groups and o-Ns-activated amino groups in polymer chain ends did not interfere with each other, well-defined telechelic PNsMAz-OH and PNsMAz-b-Poly(PO-alt-PA) were prepared. After desulfonation of these polymers using K₂CO₃ and p-thiocresol in DMF solution, the final telechelic linear polymers polypropylenimine (L-PPI-OH) and L-PPI-b-Poly(PO-alt-PA) were obtained with desulfonylation of at least 98%. With the removal of the o-Ns group, these telechelic block copolymers showed obvious hydrophilicity, ensuring their potential application in the field of biological and engineering materials.