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Advisor(s)
Abstract(s)
The formation of lignin-based polyurethanes was monitored by Fourier transform infrared spectroscopy
working in attenuated total reflectance mode (FTIR-ATR) and kinetics was analyzed according to a global
second order model. The used chemical system consisted of 4,40-methylene-diphenylene diisocyanate
(MDI), polycaprolactone (PCL) of three different average-molecular weights (400, 750 and 1000) and
two lignin (L) samples (Alcell (A) and Indulin AT (IAT)), incorporated at different weight contents (10%,
15%, 20% and 25%) in the polyol mixture. The polymerization reaction was carried in bulk and without
the presence of any catalyst. Results showed that isocyanate conversion decreases with the increase of
both lignin content and PCL molecular weight. Moreover, the Indulin AT series leaded to lower isocyanate
conversions compared to Alcell counterparts. The global second order treatment showed to be dependent
of lignin type and content as well as PCL molecular weight. In fact, for the studied system this model was
found to be more adequate for low lignin contents. After the region of linearity, a negative deviation was
always observed and found to be more pronounced with increasing the lignin content.
Description
Keywords
Lignin Polyurethanes FTIR monitoring Kinetics
Citation
Cateto, C.A.; Barreiro, M.F.; Rodrigues, A.E.; Belgacem, M.N. (2011). Kinetic study of the formation of lignin-based polyurethanes in bulk. Reactive and Functional Polymers. ISSN 1381-5148. Nº71, p.863-869
Publisher
Elsevier