Biobased rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application, Part 1: Synthesis, chemical, and physical properties

Abstract

Polyurethane foam is one of the most versatile construction insulation materials because of its low density, high mechanical properties, and low thermal conductivity. This study examined biobased rigid polyurethane foam composites from apricot stone shells, which are lignocellulosic residues. The apricot stone shells were liquefied with a PEG-400 (polyethylene glycol-400) and glycerin mixture in the presence of sulfuric acid catalyst at 140 to 160 °C for 120 min. Rigid polyurethane-type foam composites from the reaction were successfully prepared with different chemical components. Biobased polyurethane-type foam composites were successfully produced from the liquefied apricot stone shells. The FTIR spectra of liquefaction products confirmed successful liquefaction of products and that they are sources of hydroxyl groups. The liquefaction yield (81.6 to 96.7%), hydroxyl number (133.5 to 204.8 mg KOH per g), the highest elemental analysis amount (C, H, N, S, O) (62.08, 6.32, 6.12, 0.13, and 25.35%), and density (0.0280 to 0.0482 g per cm3) of the rigid polyurethane foam composites were comparable to foams made from commercial RPUF composites.

Bio-based rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application – Part 2: Morphological, mechanical, and thermal properties

“…The FTIR spectra of liquefaction products confirmed the successful liquefaction of products and that they are sources of hydroxyl groups. The liquefaction yield (81.6 to 96.7%), hydroxyl number (133.5 to 204.8 mg KOH per g), the highest elemental analysis amount (C, H, N, S, O) (62.08, 6.32, 6.12, 0.13, and 25.35%), and density (0.0280 to 0.0482 g per cm 3 ) of the rigid polyurethane foam composites were comparable to foams made from commercial RPUF composites (Fidan and Ertaş 2020b).…”

Production of bio‐polyurethane (BPU) foams from greenhouse/agricultural wastes, and their biodegradability

“…As shown in this Table, the BPU foams have lower densities than that of the reference foam. It has been reported that density of bio‐based PU foams derived from biomass liquefaction is typically in the range of 20 to 125 kg/m 3 19,29 . The density was found to be significantly dependent on the cell size of the foam; the larger the cell size, the lower the foam density 30 .…”

“…By comparison, the mechanical properties of BPU foams are significantly lower than those of the reference foam. The density of the foam has an influence on the mechanical properties; the higher the foam density, the greater the mechanical strength 29 . As illustrated in Table 4, reference foam had a density approximately 2 to 10 times that of BPU foams, resulting in a higher mechanical strength.…”

“…It has been reported that density of bio-based PU foams derived from biomass liquefaction is typically in the range of 20 to 125 kg/m 3 . 19,29 The density was found to be significantly dependent on the cell size of the foam; the larger the cell size, the lower the foam density. 30 It is self-evident that 10%BPU foam has the highest density of all BPU foams, most likely due to foam cell shrinkage and collapse.…”

“…The density of the foam has an influence on the mechanical properties; the higher the foam density, the greater the mechanical strength. 29 As illustrated in Table 4, reference foam had a density approximately 2 to 10 times that of BPU foams, resulting in a higher mechanical strength. Regardless of the 10%BPU, other BPU foams demonstrated a similar trend in mechanical strength with foam density changes, most notably at 10% deformation.…”