Polylactide-Grafted Metal-Alginate Aerogels

Abstract

Τhis 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.

Beeswax as a natural alternative to synthetic waxes for fabrication of PLA/diatomaceous earth composites

“…Lee added N -ethyl- and N -2-hydroxyethyl-substituted maleimide-styrene graft-block copolymer to the polylactide 20 , while in our previous work, it was found that the addition of graphite to PLA is a step towards obtaining material that is cheap and suitable for 3D printing of sliding spare parts 21 . In addition, a polylactide-based material with proper additives can help produce fibre-reinforced composite intended for use in agriculture 22 or metal alginate-grafted PLA aerogels (PLA-g-M-alginate; M: Ca 2+ , Co 2+ ,Ni 2+ , Cu 2+ ) 23 . It was previously reported that diatomaceous earth may also be used to reinforce PLA, which is beneficial for both mechanical and thermal properties of such obtained composites 24 .…”

Wet Milling of Alginate Alco‐ and Hydrogel Composites: A Facile Top‐Down Approach for Continuous Production of Aerogel Microparticles

“…Skeletal density [g cm −3 ] Reference 1.0 2.02 ± 0.08 [30] 1.0 1.92 ± 0.03 [30] 1.5 1.82 [31] 2.0 2.07 ± 0.02 [30] 2.0 1.934 ± 0.006 [30] 2.0 1.97 ± 0.03 [32] 2.0 1.95 ± 0.02 [32] 3.0 1.89 ± 0.02 [33] 3.0 1.85 [31] 5.0 0.366 [34] 5.0 1.77 [31] 6.0 1.18 ± 0.16 [35] 10.0 1.84 [31] Median value ± IQR a) 1.89 ± 0.13 a) Due to certain scattering of the literature data, the median was calculated as a measure of central tendency and the interquartile range (IQR) is a measure of statistical dispersion.…”