Melamine-urea-formaldehyde resins with their excellent properties, in particular resistance to humidity and water and colourless adhesive bond, are widely used in the wood industry. In spite of the fact that the basic reaction between melamine and formaldehyde has been known for over seventy years, the conditions of synthesis and molar ratios continue to be a matter of research. Different molar ratios of input raw materials and different conditions of synthesis have a major impact on the properties of the resin, its stability and end use behaviour. In this research project, molar ratios and conditions of synthesis of the basic resin were modifed, and the impact of each modification was analysed. As condensation reaction does not end once the synthesis is completed but merely decreases,we also analysed the properties of the so-called aged resin.
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