3.3.6. Summary of 2nd treatment
The extracted lignin through 1st treatment were depolymerized to Mw < 1000 fractions in high yields by the 2nd treatment. The results were obtained from all the types of BET-BAY 002 samples used in this study. The depolymerized lignin showed low softening temperature, which is essential for the use as resin material. Next, in the following section, the resinification profile of depolymerized lignin was examined.
3.4. Resinification of extracted depolymerized lignin
3.4.1. Resinification of lignin using hexamine as the curing agent
Fig. 11. Differential thermal analyses during curing reaction of acetone-solubles (Black lines; 2nd-acetone-solubles, Gray lines; 1st-acetone-solubles, Solid lines; cedar, Dotted lines; beech, Broken lines; rice straw).Figure optionsDownload full-size imageDownload as PowerPoint slide
Exothermic energies, the ranges of curing temperature, and the peak curing temperatures of acetone-solubles during the resinification procedure measured by DTA.SampleExothermic energy [J/g]Range of curing temperature [°C]Peak curing temperature [°C]1st-Acetone-solubleCedar42.5130–170162Beech78.3129–163153Rice straw43.5131–1721442nd-Acetone-solubleCedar76.5138–182154Beech87.7129–169145Rice straw80.5124–168155Full-size tableTable optionsView in workspaceDownload as CSV