Effects of High-Temperature Heat Treatment Modification by Impregnation on Physical and Mechanical Properties of Poplar

To expand the application range of fast-growing poplar, a modification method of poplar impregnated with nano-SiO(2) and urea-formaldehyde resin was proposed in this study. Taking the mass ratio of nano-SiO(2) mass to the solid content of urea-formaldehyde resin impregnation solution (W), high-temperature (H), and high-temperature time (T) as influencing factors, the effects of impregnation high-temperature heat treatment modification on the physical and mechanical properties of fast-growing poplar were explored. At the same time, the weight loss rate, oven-dry density, dry shrinkage properties, swelling properties, modulus of rupture (MOR), and modulus of elasticity (MOE) of the modified poplar were measured. The research results show that both the weight loss rate and the coefficient of variation of the oven-dry density have a high correlation with the temperature; the high-temperature immersion heat treatment can reduce the dry shrinkage and swelling of poplar, improve the dimensional stability, MOR, and MOE. W is 0–1%, H is 160 °C, and T is 2–4 h. The impregnated heat-treated wood has good MOR and MOE. Therefore, the combination of nano-SiO(2) and urea-formaldehyde resin impregnation and heat treatment to modify poplar can improve some physical and mechanical properties of fast-growing poplar, expand the use of poplar, increase its added value, and realize high-value utilization.