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Publication
Lignin-based polyurethane materials
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Advisor(s)
Abstract(s)
Four technical lignins (Alcell, Indulin AT, Sarkanda and Curan 27-11P) were used as macromonomers
in the synthesis of polyurethane materials following two global approaches. In the
first one Alcell and Indulin AT lignins were used directly as co-monomers in combination with
a linear polycaprolactone (PCL) in order to produce polyurethane elastomers where lignin
content varied between 10 and 25% (w/w) with respect to polyol mixture (PCL+lignin). The
thermomechanical properties of the resulting materials were determined by dynamical
mechanical analysis (DMA), differential scanning calorimetry (DSC) and swelling tests. In
lignin-based elastomers Indulin AT showed to be more efficiently incorporated in the
polyurethane network compared with Alcell lignin. Elastomers prepared with Indulin AT lignin
exhibited a cross-linking density and storage modulus (rubbery plateau) higher than those of
Alcell lignin-based counterpart and a lower soluble fraction. For both Alcell and Indulin AT
based elastomers the glass transition temperature increased and extended over a wide
temperature range with the increase of lignin content.
The second approach consisted of producing rigid polyurethane foams (RPU) using ligninbased
polyols obtained after chemical modification by an oxypropylation procedure. Two
polyol formulations (20/80 and 30/70, in what concerns the weight ratios between lignin and
propylene oxide, PO), were used in RPU formulations and their content varied from 0 to
100% (w/w with respect to a commercial polyol, used as a reference). The resulting RPU
foams were characterized in terms of density, mechanical properties, conductivity and
morphology. The prepared RPU foams with lignin-based polyols presented properties, very
similar to those obtained from conventional commercial polyols. RPU foams prepared with
30/70 polyols exhibited improved properties comparatively to those arising from 20/80
formulations. Exceptions were however detected in RPU foams prepared with all Sarkanda
lignin based polyols and Curan 27-11P 30/70 formulation, which were found to be
inadequate for RPU formulation.
Description
Keywords
Lignin Polyurethanes Bio-based Added value
Citation
Cateto, C.A.; Barreiro, M.F.; Rodrigues, A.E.; Belgacem, M.N. (2008-09) - Lignin-based polyurethane materials. In 10th International Chemical and Biological Engineering Conference - CHEMPOR. Braga. ISBN 978-972-97810-3-2
Publisher
Universidade do Minho