Characterization of polyurethane foams prepared from liquefied sawdust by crude glycerol and polyethylene glycol

Abstract

The aim of this study was to investigate polyurethane foams (PUF) properties obtained from crude glycerol (CG) and polyethylene glycol (PEG) based liquefaction of sawdust. The four types of foam were prepared by producing polyols from different weight loadings of PEG to CG as the liquefaction solvent. The produced polyurethane foams showed densities from 0.042 to 0.08 g/cm 3 and compressive strengths from 200 to 311 kPa. The foams obtained from CG/PEG based liquefaction, had more uniform and regular cell structure than foams derived from liquefaction by CG. Also with the increasing percentage of PEG to CG in liquefaction, closed cell content of the synthesized foams increased and the size of cells decreased. The thermal conductivity of the produced foams was between 0.031 and 0.040 W/m K. Foams produced from liquefaction by binary solvent had lower thermal conductivity. However all foams showed approximately similar thermal degradation curves; maximum thermal decomposition temperature was seen for the foam produced from higher weight ratio of PEG to CG in liquefaction. PU foams produced from PEG/CG based liquefaction process had improved properties over from foams derived from sawdust liquefaction by CG.

Improvement of thermal conductivity of rigid polyurethane foams with aluminum nitride filler

“…These results are also in agreement with the results reported in the literature for PU foams. 33 On the other hand, the important rise of the density by around 21% for the 40 wt.% AlN filled foam indicates a significant contribution of the density to the improvement of the thermal conductivity of the foams as reported in the literature. 29 Moreover, as the AlN fillers used in this study have a large particle size, we can deduce that when the filler content increases, the open cell content of the foams increases.…”

“…29 Moreover, as the AlN fillers used in this study have a large particle size, we can deduce that when the filler content increases, the open cell content of the foams increases. According to Rastegarfar et al, 33 when the open cell content increases, the thermal conductivity increases due to higher heat transfer in foam cells. This is also the case in our study where the thermal conductivity increases until a filler content of 10 wt.% and then almost stabilizes for foams with higher filler content.…”

An update on the future prospects of glycerol polymers

“…Due to the widespread applications of PUs, there is an intense focus to develop biobased and/or biodegradable PUs. 38 Biobased crude glycerol has been widely studied as the precursor for PUs, [39][40][41] even for specific applications such as thermal energy insulators, 42,43 waterborne films [44][45][46] and sound absorbers. 47 Crude glycerol is typically heated under vacuum at temperatures between 150-200°C for 2-5 h to synthesize polyols.…”

Quantitative Pore Characterization of Polyurethane Foam with Cost-Effective Imaging Tools and Image Analysis: A Proof-Of-Principle Study

“…They can be recycled or recovered after use to reduce production costs and increase material utilization efficiency [3]. Thermosetting polymers like PU foams are widely preferred due to their light weight, excellent biocompatibility, flexible mechanical properties, and the presence of a urethane linkage (–NH–CO–O–) that bonds easily with nanoparticles such as silver nanoparticles (AgNPs) [4,5,6,7,8,9,10]. Also, PU foams have the capability of delivering a wide range of cell structures, rigidity, strength, and durability.…”

“…Abramoff et al [29] reported the determination of pore sizes, pore size distribution, and other pore morphologies using FIJI/ImageJ from scanning electron microscope micrographs and a JEOL Model JSM-6490. A study by Rastegarfar et al showed the characterization of PU foams produced from liquefied sawdust using SEM, among other techniques [8]. Bachtiar et al recently investigated the thermal stability and fire resistance of flax fabric-reinforced polymer composites with the help of SEM [30].…”