Characterization of Biobased Polyurethane Foams Employing Lignin Fractionated from Microwave Liquefied Switchgrass

Figure 2

FTIR spectra of (1) polyol, (2) Switchgrass lignin, and (3) MDI; (A) pure polyol, (B) 5% lignin, (C) 10% lignin, and (D) 15% lignin content polyurethane foams.

(a)

(b)