<i><i>N,N</i></i>-Diallylglycidylamine: A Key Monomer for Amino-Functional Poly(ethylene glycol) Architectures

Abstract

The first application of <i><i>N,N</i></i>-diallylglycidylamine (DAGA) as a monomer for anionic ring-opening polymerization is presented. The monomer is obtained in a one-step procedure using epichlorohydrin and <i><i>N,N</i></i>-diallylamine. Both random and block copolymers consisting of poly­(ethylene glycol) and poly­(<i><i>N,N</i></i>-diallylglycidylamine) with adjusted DAGA ratios from 2.5 to 24% have been prepared, yielding well-defined materials with low polydispersities (<i>M</i>_w/<i>M</i>_n) in the range 1.04–1.19. Molecular weights ranged between 2600 and 10 300 g mol^–1. Isomerization of allylamine to enamine structures during polymerization depending on time, temperature, and counterion has been realized. The kinetics of the formation of the copolymer structure obtained by random copolymerization was investigated, using time-resolved ¹H NMR measurements and ¹³C NMR triad sequence analysis. A tapered character of the monomer incorporation was revealed in the course of the concurrent copolymerization of EO and DAGA. The thermal behavior of the copolymers in both bulk and aqueous solution has been studied, revealing LCSTs in the range 29–94 °C. Quantitative removal of protective groups via double-bond isomerization mediated by Wilkinson’s catalyst and subsequent acidic hydrolysis yielded multiamino-functional PEG copolymers with tapered or block structure. Accessibility of liberated primary amines for further transformation was demonstrated in a model reaction by derivatization with acetic anhydride. In contrast to previous approaches, the DAGA monomer permits the synthesis of block copolymers with PEG block combined with multiamino-functional polyether block