Official Journal of the Japan Wood Research Society
Table 3 Density and compressive properties of the PU and W–PU foams containing varying contents of lignin perpendicular to foam rise
Sample | Density (kg/m3) | Compressive strength (KPa) | Compressive modulus (MPa) | Specific compressive strength (MPa/(g cm−3)) | Specific compressive modulus (MPa/(g cm−3)) |
|---|---|---|---|---|---|
PU | 62 ± 2 | 330 ± 17 | 8.15 ± 1.30 | 4.63 ± 0.31 | 90.3 ± 4.6 |
PU/L5 | 100 ± 7 | 728 ± 35 | 10.07 ± 0.89 | 7.16 ± 0.32 | 114.1 ± 12.3 |
PU/L10 | 108 ± 7 | 690 ± 48 | 10.39 ± 1.88 | 5.83 ± 0.85 | 119.7 ± 7.2 |
PU/L15 | 111 ± 3 | 658 ± 52 | 10.54 ± 1.21 | 4.99 ± 0.48 | 102.6 ± 7.4 |
PU/L20 | 115 ± 4 | 642 ± 71 | 14.72 ± 2.86 | 4.26 ± 0.46 | 80.4 ± 4.9 |
W–PU | 47 ± 4 | 56 ± 8 | 0.74 ± 0.07 | 1.08 ± 0.17 | 12.8 ± 2.2 |
W–PU/L5 | 52 ± 3 | 62 ± 2 | 0.95 ± 0.08 | 1.10 ± 0.05 | 16.0 ± 1.2 |
W–PU/L10 | 72 ± 1 | 84 ± 5 | 1.16 ± 0.01 | 1.23 ± 0.16 | 16.6 ± 1.3 |
W–PU/L15 | 84 ± 6 | 98 ± 14 | 1.73 ± 0.04 | 1.25 ± 0.03 | 19.2 ± 2.2 |
W–PU/L20 | 96 ± 5 | 113 ± 8 | 2.16 ± 0.10 | 1.68 ± 0.19 | 19.0 ± 1.1 |