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width of the particles respectively. The particles, generated in a disk chipper, were obtained with a thickness of approximately 0.7 mm. These parameters were selected, once that are the parameters used by OSB industries. Table 1 shows the differences in the panels. Table 1. OSB Types Subjected to MIP Test
OSB type
OSB density (kg/m³)
Resin content (%)
Wood species
Resin
OSB1
Pinus sp.
Phenol-formaldehyde
600
8
Castor oil-based polyurethane Castor oil-based polyurethane Castor oil-based polyurethane Castor oil-based polyurethane
Schizolobium amazonicum Schizolobium amazonicum
OSB 2
650
10
OSB 3
650
12
OSB 4
Pinus sp. Corymbia citriodora
700
12
OSB 5
750
12
Methods The mercury intrusion porosimetry method is based on the isostatic injection, under very high pressure (several hundred megapascals), of a non-wetting fluid (mercury) into the porous material (Zhao et al. 2021). For this study, it is important to highlight that the mercury intrusion porosimetry technique was developed based on the studies of Bertolini (2004) and Varanda (2016), which analyzed this property for wood-based panels. The pore size distribution is determined from the volume intruded at each pressure increment, and total porosity is determined from the total volume intruded (Abell et al. 1999). MIP tests were performed with a Micromeritics Poresizer (model 9320, Sao Calos, Brazil) with a maximum 200 MPa injection pressure. Parameters such as total intrusion volume (mL/g), total pore area (m 2 /g), average pore diameter (μm), bulk density (mL/g), skeletal density (mL/g), and porosity (%) were determined. The specimens had dimensions of 14 mm width and 23 mm length. In total, it was used two samples for each OSB type. They were dried in an oven with air circulation at 50 °C for 24 h before the test. The MIP parameters for were as follows: mercury with a surface tension of 0.494 g/cm 2 and density of 13.533 g/mL, advancing and rewind contact angle of 130°, and equilibrium time between the low and high pressure of 10 seconds. RESULTS AND DISCUSSION Figure 1 shows the pore size distribution of the specimens obtained by plotting the log differential intrusion volume d V /d P versus the pore diameter. OSB 1 had a greater number of pores with diameters smaller than 0.05 μm, and there was a small pore amount in the range of 0.2 and 0.8 μm. There were few pores above 11 μm. For OSB 2, there were more pores with diameters below 0.04 μm and a considerable number with dimensions between 7 and 12 μm. In OSB 3, there were two pore size distribution ranges, the predominant band at less than 0.04 μm and another betwe en 8 and 16 μm. For OSB 4, the most pores were below 0.02 μm; there was a small number of pores in the range of 0.2 to 1 μm , and others in the range 8 to 12 μm. Finally, for OSB 5, there were more pore s in the
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Ferro et al . (20 21). “Strandboard Hg porosimetry,” B io R esources 16(4), 6661-6668.
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