A highly
easy and efficient metal-free methodology for the synthesis
of polyaziridine-based polymers with controlled architectures and
desired functionalities was developed by organocatalytic ring-opening
polymerization (ROP) of N-sulfonyl aziridines with
a carboxylic acid as initiator. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene
(MTBD) and phosphazene t-Bu-P4 organocatalysts
have demonstrated high catalytic efficiency in connection with the
controlled/living character of the ROP of 2-methyl-N-tosylaziridines (TsMAz) initiated by benzoic acid. Aryl carboxylic
acids bearing an azido or a hydroxyl group as well as bio-derived
vanillic acid and syringic acid and alkyl- and alkenyl-substituted
carboxylic acids, such as acetic acid, palmitic acid, and methacrylic
acid, can all initiate the ROP of TsMAz toward well-defined P(TsMAz)s.
α,ω-Diamino telechelic, star-shaped P(TsMAz)s, and poly(styrene-co-methacrylic acid)-graft-poly(2-methyl-N-tosylaziridine) [P(St-co-MAA)-g-P(TsMAz)] have been conveniently synthesized from the
corresponding multicarboxyl (macro)initiators. Finally, this protocol
has been applied for the synthesis of a linear photoresponsive P(TsMAz)
and an aggregation-induced emission (AIE)-active 4-arm P(TsMAz) star
from the corresponding functionalized carboxylic acids.