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

Figure 1

SEM images of (a) pure polyol, (b) 5% lignin, (c) 10% lignin, and (d) 15% lignin content polyurethane foams.

(a)

(b)

(c)

(d)