Poly(glycerol itaconate) Crosslinking via the aza-Michael Reaction-A Preliminary Research.

In unsaturated glycerol polyesters, the C=C bond is present. It makes it possible to carry out post-polymerisation modification (PPM) reactions, such as aza-Michael addition. This reaction can conduct crosslinking under in-situ conditions for tissue engineering regeneration. Until now, no description of such use of aza-Michael addition has been described. This work aims to crosslink the synthesised poly(glycerol itaconate) (PGItc; P3), polyester from itaconic acid (Ac Itc ), and glycerol (G). The PGItc syntheses were performed in three ways: without a catalyst, in the presence of p -toluenesulfonic acid (PTSA), and in the presence of zinc acetate (Zn(OAc) 2 ). PGItc obtained with Zn(OAc) 2 (150 °C, 4 h, G:Ac Itc = 2:1) was used to carry out the aza-Michael additions. Crosslinking reactions were conducted with each of the five aliphatic diamines: 1,2-ethylenediamine (1,2-EDA; A1), 1,4-butanediamine (1,4-BDA; A2), 1,6-hexanediamine (1,6-HDA; A3), 1,8-octanediamine (1,8-ODA; A4), and 1,10-decanediamine (1,10-DDA; A5). Four ratios of the proton amine group: C=C bond were investigated. The maximum temperature and crosslinking time were measured to select the best amine for the addition product's application. FTIR, 1 H NMR, DSC, and TG analysis of the crosslinked products were also investigated.