Study On Urea Formaldehyde Resin Adhesive Modified By Phenol-oil Extracted From Bio-oil

In order to improve the bonding strength and formaldehyde emission content of wood products bonded by UF resin, phenol-oil sperated from bio-oil were used to modify UF resin. In this thesis, gas chromatography mass spectrometry (GC-MS) and gas chromatography (GC) were used to study the extraction efficiency of different solvents and extraction methods to different race compounds. The phenol-oil extracted from bio-oil was analyzed by GC-MS. Performances of UF.modified by phenol-oil, were studied, through measuring bonding strength, formaldehyde emission content, curing time and eramined by FTIR. With bonding strength and formaldehyde emission content as evaluation standard, the parameters of hot-pressing process were also studied. The main conclusions are as follows:(1) Physical and chemical properties of larch bio-oil were complex. The difference of moisture content (40%) from other bio-oil was large. However, the difference of other physical characteristics, such as density, pH, dynamic viscosity and ash content, was small. Lach bio-ois included acids(21.52%), aldehydes (16.15%), phenols and their derivatives (20.64%), esters (10.53%), ketones (12.15%), sugars(5.12%) and other components (13.89%, basically including hydrocarbons, ethers and furan compounds).(2) Differences of extraction efficiency of different solvents and extraction methods to different race compounds were quite large. Of all the solvents, methylene chloride and ethyl acetate worked best, butyl acetate esters took second place, cyclohexane worst. The extraction efficiency of methylene chloride and ethyl acetate to phenols and aldehydes was best, butyl acetate ester had best efficiency to acids, and the best efficiency to ketones was toluene. Extraction efficiency of multi-stage reverse extraction was better than single stage extraction.(3) The substances content of phenols in phenol-oil was53.87%, which including phenol (4.54%), guaiacol (10.06%),2-hydroxy-5-methyl phenol (14.14%). The optimum modification condition was F/U molar ratio of1.2, phenol-oil added with the first batch of urea, the addition amount of phenol-oil was10%of total ureas.(4) It was concluded that benzene structure of phenol-oil had been successfully introduced in urea formaldehyde resin according to FTIR analysis. The optimum hot-pressing condition was hot pressing temperature of125℃, hot pressing time for5min.