The
need for renewable alternatives for fossil-based aromatic material
constituents is evident for a more sustainable society. Lignin is
the largest source of naturally occurring aromatic compounds but has
mainly been considered as waste material or energy source in the pulp
and paper industry. Developments in extracting lignin from these processes
provide a large source for renewable aromatic structures to be used
in various applications. Producing thermosets out of lignin is a very
promising route to utilize this raw material toward, for example,
composite application. The buildup of the molecular network based
on oligomeric lignin segments will be different from traditional thermoset
analogues, where the constituents often are smaller molecules, and
will have an effect on the material properties. In this work LignoBoost
Kraft lignin is refined, chemically modified, and used to produce
freestanding thermosets with different architectures and properties.
These different thermosets are evaluated, and the possibilities to
tailor the material properties through work-up and modification are
demonstrated. Morphological studies on the formed thermosets using
X-ray scattering show systematic differences in molecular stacking
and aggregate sizes.