Production of a bio-material composed with polyurethane foam and heat treated wood fibers

Overview & Synopsis

The work was divided in three parts: - Synthesize a novel polyol from macaúba kernel oil and glycerol, a product that is often treated as waste. This polyol is then used to produce polyurethane (PU) foams with different NCO/OH ratio, whose synthesis were confirmed by FTIR and 1H NMR., though the results of the samples were quite similar, specially the samples with 1.0 and 1.2 NCO/OH ratios. - Test different thermal treatment by pyrolysis, to modified by thermodegradation the wood and particularly the hemicelluloses and the cellulose. These treatments were done with three different wood species, beech, fir and carvoeiro. These wood species are very common in Europa or in Brazil. The chemical modification is qualified by indirect technics like mass loss, derivative thermogravimetry (DTG) deconvolution and delignification, with all techniques pointing to a single ideal treatment temperature for each wood species-Preparation of composite using the PU synthesized in the first part of this work and the thermally treated woods produced in the second part of the work. The treated woods were ground and the <250µm particle size was chosen based on literature and by attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy revealing that this particle size presented great amounts of surface -OH to be reacted with the isocyanate. The produced PUs, except the PU made with a 1.0 NCO/OH ration, labelled PU 1.0 sample, presented four DTG degradation peaks, instead of the usual 3 seen in PUs, indicating the reaction of the NCO with the novel polyol created segments of intermediate rigidities, likely due to crosslinking. The 4 peaks were also seen in the composites, even the composites with 1.0 NCO/OH ratio, though usually having the intermediate DTG peaks considerably smaller, showing the reaction favored the formation of rigid and soft segments over the intermediate rigidities. The PUs and composites were also tested by DVS. While the PUs and the 2% raw wood composites showed low and similar water uptake, both the 2% treated wood composite and 5% raw composite presents considerably higher water uptakes, likely due to increase in mesoporosity in the polymeric matrix.