Figure 5.

(A) Monomer yields of boron lignin extracted from beechwood following immediate transfer to an inert atmosphere glovebox without concentration and after storage of the same sample for 3 months. (B) Monomer yields of boron lignin extracted from beechwood following immediate transfer to an inert atmosphere glovebox without concentration, and for samples that were concentrated with rotary evaporation. Both preparations were performed in triplicate. (C) Progressive monomer degradation of the beechwood monomer oil upon exposure to air. Longer exposure time resulted in a strong color change from a pale yellow after workup to a light pink 5 min after workup to a dark brown 15 min after workup. The color change was accompanied with the formation of insoluble particulates. Yields shown are the average of three samples; student’s t-test was used for statistical comparison. ns = not significant.