Sustainable aerogels derived from bio-based 2,5-diformylfuran and depolymerization products of lignin

Figures & data

Figure 1. Schematic diagrams illustrating the primary reactants and procedures employed in this work to produce bio-based aerogels

Figure 2. ¹H-NMR spectra in CDCl₃ a) of the obtained product, b) of 2,5-diformylfuran obtained from Sigma-Aldrich and c) of 5-(hydroxymethyl)furfural used for the synthesis

Table 1. Phenolic compounds screened in this study for gelation with DFF and F

Phenolic compounds	Molar ratio of aldehydic to phenolic compounds
	DFF (1:1)	F (1:1)	F (1:2)	F (1:3)
Resorcinol	+	-	+	+
Phloroglucinol	+	-	+	+
Catechol	+	+	+	+

Reaction conditions: solid content: 15%, sample size: 1 g, solvent: water, catalyst: NaOH, pH: 10–11 and reaction temperature: 24 h at RT, 24 h at 323 K, 72 h at 363 K

+ indicates gelation after specified reaction time

- indicates that no gelation was observed

Table 2. Specific BET surface areas of the aerogels investigated

sample no.	pH^a	aldehydic component	phenolic component	A:P^b	Sample weight/g	SBET^c/m[^2]g^−1
A1	10.8	F	resorcinol	2	10	330.1
A2	10.4	F	phloroglucinol	2	10	93.0
A3	10.5	F	catechol	2	10	289.0
A4	10.6	F	catechol	1	1	475.4
B1	10.3	DFF	resorcinol	1	1	75.1
B2	10.9	DFF	phloroglucinol	1	1	719.4
B3	10.4	DFF	catechol	1	1	13.8
B4	10.5	DFF	resorcinol	1	10	150.4
B5	10.7	DFF	phloroglucinol	1	10	218.8

^apH of reaction solution prior to curing process. ^b molar ratio of aldehyde (A) to phenolic (P) compounds. ^c specific BET surface area of the aerogel.

Figure 3. SEM images of DFF aerogels with a) phloroglucinol, b) resorcinol and c) catechol, and of F aerogels with d) phloroglucinol, e) resorcinol and f) catechol

Figure 4. TGA curves of a) all aerogels prepared and b) of catechol-F and catechol-DFF aerogels including derivative thermogravimetric (DTG) curves for direct comparison

Delidovich I, Leonhard K, Palkovits R. Cellulose and hemicellulose valorisation: an integrated challenge of catalysis and reaction engineering. Energy Environ Sci. 2014;7:2803.

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Data availability statement

Data availability statement Data will be made available upon request to the corresponding author at [email protected]; www.wood-kplus.at.