TY - JOUR
T1 - Penetration of urea-formaldehyde resins with different formaldehyde/urea mole ratios into softwood tissues
AU - Nuryawan, Arif
AU - Park, Byung Dae
AU - Singh, Adya P.
PY - 2014/9
Y1 - 2014/9
N2 - In order to understand the impact of formaldehyde/urea (F/U) mole ratio on penetration characteristics of urea-formaldehyde (UF) resin into softwood tissues, a quantitative measurement of UF resin penetration into radiata pine (Pinus radiata) tissues from the bond-line was undertaken. Four different F/U mole ratios (1.6, 1.4, 1.2, and 1.0) of UF resins with different viscosities and two levels of hardener (NH4Cl) for two extreme F/U mole ratios (1.6 and 1.0) were studied. Firstly, field emission scanning electron microscope and confocal laser scanning microscopy were used to localize UF resins in the bond-line for the qualitative evaluation of resin penetration. Then light microscopy was employed to quantitatively measure the resin penetration and bond-line thickness. A decrease in the F/U mole ratio of UF resin that proportionately decreased the resin viscosity resulted in an increase in the average resin penetration and a decrease in the bond-line thickness. Higher hardener level provided a greater resin penetration with all F/U mole ratio UF resins. These results demonstrated that F/U mole ratio had an impact on the penetration and bond-line thickness of UF resins, owing to differences in the reactivity of resins, with higher F/U mole ratio resins being more reactive.
AB - In order to understand the impact of formaldehyde/urea (F/U) mole ratio on penetration characteristics of urea-formaldehyde (UF) resin into softwood tissues, a quantitative measurement of UF resin penetration into radiata pine (Pinus radiata) tissues from the bond-line was undertaken. Four different F/U mole ratios (1.6, 1.4, 1.2, and 1.0) of UF resins with different viscosities and two levels of hardener (NH4Cl) for two extreme F/U mole ratios (1.6 and 1.0) were studied. Firstly, field emission scanning electron microscope and confocal laser scanning microscopy were used to localize UF resins in the bond-line for the qualitative evaluation of resin penetration. Then light microscopy was employed to quantitatively measure the resin penetration and bond-line thickness. A decrease in the F/U mole ratio of UF resin that proportionately decreased the resin viscosity resulted in an increase in the average resin penetration and a decrease in the bond-line thickness. Higher hardener level provided a greater resin penetration with all F/U mole ratio UF resins. These results demonstrated that F/U mole ratio had an impact on the penetration and bond-line thickness of UF resins, owing to differences in the reactivity of resins, with higher F/U mole ratio resins being more reactive.
UR - http://www.scopus.com/inward/record.url?scp=84906062884&partnerID=8YFLogxK
U2 - 10.1007/s00226-014-0649-9
DO - 10.1007/s00226-014-0649-9
M3 - Article
AN - SCOPUS:84906062884
SN - 0043-7719
VL - 48
SP - 889
EP - 902
JO - Wood Science and Technology
JF - Wood Science and Technology
IS - 5
ER -