Fig. 4
From: Wood morphology and properties from molecular perspectives
Polar graph (0o to 90o) of the absorbance (1,508 cm−1) of middle lamella lignin and secondary wall lignin (Salmén et al. 2012). The secondary wall lignin shows a small degree of orientation while the middle lamella lignin is completely isotropic. The dotted line indicates the case of a completely isotropic orientation