Effects of urea and curing catalysts added to the strand board core-layer binder phenol–formaldehyde resin
| Autor: | Moon G. Kim, Sang M. Lee |
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| Rok vydání: | 2007 |
| Předmět: |
chemistry.chemical_classification
Polymers and Plastics Formaldehyde Concentration effect General Chemistry Oriented strand board Surfaces Coatings and Films chemistry.chemical_compound chemistry Polymerization Phenol formaldehyde resin Polymer chemistry Materials Chemistry Urea Adhesive Curing (chemistry) Nuclear chemistry |
| Zdroj: | Journal of Applied Polymer Science. 105:1144-1155 |
| ISSN: | 1097-4628 0021-8995 |
| Popis: | Effects of adding urea to the strand board core-layer phenol–formaldehyde (PF) resin were investigated in conjunction with cure-accelerating catalysts. Ten percent urea based on the liquid resin weight was added at the beginning, at three different middle stages of polymerization, and at the end of PF resin synthesis. No significant cocondensation between the urea and PF resin components occurred as identified by 13C NMR analyses, which corroborated well with the curing and strand board bonding performance test results. The various urea addition methods resulted in resins that slightly differ in the various tests due to the urea's temporary holding capacity of formaldehyde. The preferred method of urea addition was found to do it in the later part of PF resin synthesis for convenience, consistency, and slightly better overall performance. Some cure-accelerating catalysts were shown to reduce the thickness swelling of strand boards. This study showed the usefulness of adding some urea to strand board core-layer binder PF resins of replacing higher cost phenolic components with lower cost urea. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 |
| Databáze: | OpenAIRE |
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