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.
The procedure for the liquefaction of apricot stone shells was reported in Part 1. Part 2 of this work determines the morphological, mechanical, and thermal properties of the bio-based rigid polyurethane foam composites (RPUFc). In this study, the thermal conductivity, compressive strength, compressive modulus, thermogravimetric analysis, flammability tests (horizontal burning and limited oxygen index (LOI)) in the flame retardants), and scanning electron microscope (SEM) (cell diameter in the SEM) tests of the RPUFc were performed and compared with control samples. The results showed the thermal conductivity (0.0342 to 0.0362 mW/mK), compressive strength (10.5 to 14.9 kPa), compressive modulus (179.9 to 180.3 kPa), decomposition and residue in the thermogravimetric analysis (230 to 491 °C, 15.31 to 21.61%), UL-94 and LOI in the flame retardants (539.5 to 591.1 mm/min, 17.8 to 18.5%), and cell diameter in the SEM (50.6 to 347.5 μm) of RPUFc attained from liquefied biomass. The results were similar to those of foams obtained from industrial RPUFs, and demonstrated that bio-based RPUFc obtained from liquefied apricot stone shells could be used as a reinforcement filler in the preparation of RPUFs, specifically in construction and insulation materials. Moreover, liquefied apricot stone shell products have potential to be fabricated into rigid polyurethane foam composites.
Chemical Composition of Oleoresin and Larvae Gallery Resin of Pinus Brutia Attacked byDioryc tria Sylvestrella Ratz.Kemijski sastav oleorezina i smole galerije ličinki sa stabla bora (Pinus brutia) napadnutoga insektima Dioryctria sylvestrella Ratz. Received -prispjelo: 27. 2. 2014. Accepted -prihvaćeno: 20. 5. 2015 630*813.27; 674.032.475.4 doi:10.5552/drind.2015
Original scientifi c paper • Izvorni znanstveni rad
The present study investigated the effect of various types of impregnating and surface treatment materials on the fire resistance of wood material indoors and outdoors. Wood samples (Cedrus libani A. Rich.) were impregnated with Wolmanit-CB or Tanalith-E according to ASTM D1413‐76 (American Society for Testing and Materials 1976). The impregnated surface was treated with either synthetic or water-based outdoor varnish materials. The impregnated and varnished samples were left in outdoor conditions for 1 year. The combustion characteristics of the samples were investigated at the end of 1 year according to the combustion parameters detailed in the ASTM E160‐50 (1975) combustion test. The results of this study indicated that the combustion parameters were lower in the 1-year-old samples (89.12% of control values), in the samples impregnated using Wolmanit-CB (89.18% of control values), and in samples treated using water-based varnish (88.43% of control values). The analysis of flue gas indicated that the O2 content of the 1-year-old samples impregnated with Wolmanit-CB and treated with synthetic varnish was higher, whereas the CO content was lower. In conclusion, impregnated Wolmanit-CB specimens provide higher fire resistance.
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