Please use this identifier to cite or link to this item: https://hdl.handle.net/10216/115636
Author(s): Ana Antunes
Ana Gomes
Nádia Paiva
João Ferra
Jorge Martins
Luísa Carvalho
Ana Barros Timmons
Fernão D. Magalhães
Title: Blocked melamine-urea-formaldehyde resins and their usage in agglomerated cork panels
Issue Date: 2018
Abstract: Caprolactam and o-p-toluenesulfonamide are tested as chain-growth blockers for melamine-urea-formaldehyde (MUF) resins, in an attempt to reduce the crosslinking density of the cured resin and hence improve its flexibility. Agglomerated cork panels, for which flexibility is a technical demand, were produced with the modified resins and tested. The blockers were added at three different steps in the synthesis process: methylolation, condensation, and at the end of the synthesis. Besides evaluation of standard properties, resins were characterized using gel permeation chromatography and Fourier transform infrared. Blocked resins showed better storage stability and improved water tolerance, especially when caprolactam was employed. When used as binders in agglomerated cork panels, the blocked resins allowed for significantly better flexibility, evaluated in terms of mandrel bending test. The tensile resistance of the panels remained well within the desired limits for this type of material.
URI: https://hdl.handle.net/10216/115636
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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