Data on making uniform lignin building blocks via in-situ real-time monitoring of hydroxyethyl modification

Abstract

In this work, a lab-designed apparatus was developed to collect and record the CO 2 amount during the hydroxyethyl modification of lignin. We presented the CO 2 volume amount and the production rate under different reaction conditions (80 – 120 °C and 2 – 6 hrs). Nuclear magnetic resonance spectroscopy was performed to analyze the chemical structure of the hydroxyethyl lignin corresponding with different amounts of CO 2 that evolved during the reaction. The aliphatic hydroxyl, aromatic hydroxyl, and carboxylic acid groups were analyzed and tabulated. The acetylated hydroxyethyl lignin samples were characterized by 13 C NMR to obtain the aliphatic hydroxyl (primary and secondary), phenol (ortho substituted and ortho-free), hydroxyethyl, methoxy, and aromatic hydrogen groups semi-quantitatively. Fourier-transform infrared (FTIR) spectroscopy was adopted to analyze the surface functional groups including alkyl aryl ether bond, carboxylic acid groups, and aromatic hydroxyl groups. Gel permeation chromatography combined with a multi-angle light scattering detector and differential refractive index detector were used to obtain the molar mass of lignin before and after the modification.

One-pot route to convert technical lignin into versatile lignin esters for tailored bioplastics and sustainable materials

“…The previous Please do not adjust margins Please do not adjust margins study showed that the other lignins have enhanced solubility with EC. 47,55 This simple solventless system using less-toxic and stable reagent can minimize the workload, cost, and energy consumption for the subsequent isolation and purification, resulting in decreased PMI-water and PMI-solvent. Isolating PA from water has been thoroughly studied by previous biochemists, demonstrating good recovery efficacy.…”

“…W f is the weight of esterified lignin fraction (g), W l is the weight of original lignin (g), M1 is the change of ArOH groups and COOH groups (mmol/g), M2 is the AlOH groups in the HELignin (4.05 mmol/g) estimated using our previous data. 33,55…”

“…The obtained molecular weight traces were recorded and analyzed using Astra 6.1 software. 55 With molar mass ranging from the highest 751.5 kDa to the lowest 2.4 kDa, the PSS standard samples were analyzed and exported as the standard curve for the conventional (dRI traces) and universal (IV traces) calibration analysis by the ASTRA 6.1 software. (Table S2) The dRI traces were also adopted for the refractive index increment (dn/dc) value calculation, assuming 100% mass recovery and high purity for selected dRI peaks of each fraction in DMSO/LiBr (0.5%w/v).…”

Thermo-Responsive Shape-Memory Polyurethane Foams from Renewable Lignin Resources with Tunable Structures–Properties and Enhanced Temperature Resistance

“…The lignin solutions were prepared following the protocol in our previous 31 P and 13 C NMR analysis methods. 42 The lignin solutions were then transferred into 5 mm NMR tubes and analyzed using a 300 MHz NMR spectrometer (Bruker Corp.) with a broad-band observe probe at 25 °C. By adopting inverse-gated decoupling NMR, quantitative 31 P and 13 C NMR spectra were obtained using the following parameters: scan number (800 for 31 P and 20,000 for 13 C), relaxation delay (5 s for 31 P and 2s for 13 C), acquisition time (1.4 s), and pulse length (8.5 μs for 31 P and 6 μs for 13 C).…”

“…The lignin solutions were prepared following the protocol in our previous 31 P and 13 C NMR analysis methods . The lignin solutions were then transferred into 5 mm NMR tubes and analyzed using a 300 MHz NMR spectrometer (Bruker Corp.) with a broad-band observe probe at 25 °C.…”