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In this study,plantation poplar wood was first impregnated by low molecular weight phenol-formaldehyde(PF) resin solution by vacuum-pressure process.And then the wettability of sanded and non-sanded radial and tangential sections from un-impregnated and impregnated poplar wood was tested respectively by the measurement of contact angles using different liquids.Finally,the surface free energy of different samples was estimated by the plot extrapolation method.The results showed that the wettability of wood declined after impregnation with PF resin,but it could be improved by sanding;and the contact angle decreased with increasing surface free energy.Both wood texture and testing liquid affected the wettability.The sequence of the three chemical reagents is:diiodomethane (good)>formamide(medium)>distilled water(bad).
In this study, plantation poplar wood was first impregnated by low molecular weight phenol-formaldehyde (PF) resin solution by vacuum-pressure process. And then the wettability of sanded and non-sanded radial and tangential sections from un-impregnated and impregnated poplar wood was tested respectively by the measurement of contact angles using different liquids.Finally, the surface free energy of different samples was estimated by the plot extrapolation method. The results showed that the wettability of wood declined after impregnation with PF resin, but it could be improved by sanding; and the contact angle decreased with increasing surface free energy.Both wood texture and testing liquid affected the wettability. The sequence of the three chemical reagents is: diiodomethane (good)> formamide (medium)> distilled water (bad).