Abstract:
This work describes the synthesis of PLA-grafted M-alginate (g-M-alginate; M: Ca2+, Co2+, Ni2+, Cu2+) aerogels. DL-lactide (LA) was attached on the surface of preformed M-alginate beads and was polymerized, using stannous octoate as catalyst and the –OH groups of the alginate backbone as initiators/points of attachment. The material properties of g-M-alginate aerogels were not affected much by grafting, because the linear PLA chains grew on the M-alginate framework like a brush and did not bridge their points of attachment as in polyurea-crosslinked M-alginate aerogels. Thus, all g-M-alginate aerogels retained the fibrous morphology of their parent M-alginate aerogels, and they were lightweight (bulk densities up to 0.24 g cm−3), macroporous/mesoporous materials with high porosities (up to 96% v/v). The BET surface areas were in the range of 154–542 m2 g−1, depending on the metal, the nature of the alginate framework and the PLA content. The latter was found at about 15% w/w for Ca-and Ni-based materials and at about 29% w/w for Co-and Cu-based materials. Overall, we have demonstrated a new methodology for the functionalization of alginate aerogels that opens the way to the synthesis of polylactide-crosslinked alginate aerogels with the use of multifunctional monomers. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Authors:
Raptopoulos, G.
Choinopoulos, I.
Kontoes-Georgoudakis, F.
Paraskevopoulou, P.
Keywords:
Alginate; Grafting (chemical); Morphology; Polyesters, Alginate aerogels; Alginate beads; Ca 2+; Crosslinked; DL-lactide; Poly lactide; Polylactide-g-alginate; Stannous octoate; ]+ catalyst, Aerogels
