Effect of Sepiolite-Loaded Fe₂O₃ on Flame Retardancy of Waterborne Polyurethane

Figure 7

SEM images of carbon residues: (a, d) Cotton@S-2, (b, e) Cotton@S-3, and (c, f) Cotton@S-4.

(a)

(b)

(c)

(d)

(e)

(f)