Contact angle measurements were carried out with water using
a Dataphysics Contact angle system OCA 20, in order to determine
the changes in the hydrophilic character of lignin, before and
after modification. Uniform pellets have been used for this propose.
Composites were also analyzed in order to determine changes in the
hydrophilic character of each sample, before and after hydrolytic
degradation. The contact angle was read immediately in order to
determine the higroscopicity of each material. Sample thicknesses
oscillate between 0.76–0.43mm. All measurements were carried
out with water, and each sample was measured with a minimum
of five drops.