Factor Affecting Gel Time/Process-Ability of Urea Formaldehyde Resin Based Wood Adhesives
نویسندگان
چکیده
منابع مشابه
Structure formation in urea-formaldehyde resin synthesis
The structure formation in acid promoted polycondensation and particularly in alkaline post-treatment with urea was studied by 13C NMR spectroscopy in the three-step synthesis of ureaformaldehyde resins. Trishydroxymethyl urea was identified as the constituent of the mixture of hydroxylmethylated urea derivatives obtained in alkaline conditions. The formation of methylenes linked to secondary o...
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Characterization of the adhesive penetration behavior in wood is highly desired for optimizing the manufacturing processes and product properties. In this study, modified urea-formaldehyde (UF) adhesive was used to prepare glued laminated timber (Cryptomeria fortunei Hooibrenk). The depth of gross penetration was measured by fluorescence microscopy (FM), which showed the UF passed through 1.5 t...
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Maritime pine (Pinus pinaster) sawdust was used to produce liquefied wood by the polyhydric method with acid catalysis. The process was optimized to produce the highest amount of liquefied wood. Wood liquefied at 160oC for 90 min was used in the adhesion tests. The bond strength of veneer glued with ureaformaldehyde and melamine-urea-formaldehyde resins and several mixtures of liquefied wood wi...
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Adhesives products and demand for them in China are discussed in this paper with special emphasis on wood adhesives products in this decade. In 1994, the wood industries in China consumed more than 330,000 tons of adhesives. The estimated demand for wood adhesives will be more than 560,000 tons in the year 2000. The main wood adhesive used is urea-formaldehyde resin. Its consumption in 1994. wa...
متن کاملUrea–Formaldehyde-Resin Gel Time As Affected by the pH Value, Solid Content, and Catalyst
An experiment was conducted to investigate the effects of the resin solid content, catalyst content, and pH value obtained by the addition of two kinds of catalysts on the gel time of a urea–formaldehyde (UF) resin. Upon the addition of ammonium chloride, the pH value of the resin mixture decreased to 7 but not significantly further because of the limited free formaldehyde in the system. The pH...
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ژورنال
عنوان ژورنال: Open Journal of Polymer Chemistry
سال: 2017
ISSN: 2165-6681,2165-6711
DOI: 10.4236/ojpchem.2017.72003