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Influence of preparation parameters on the CHT curing diagrams of MUF polycondensation resins
Author(s) -
Properzi M.,
Pizzi A.,
Uzielli L.
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1730
Subject(s) - curing (chemistry) , condensation polymer , adhesive , urea formaldehyde , materials science , polymer chemistry , molar ratio , hardening (computing) , formaldehyde , chemical engineering , composite material , chemistry , organic chemistry , catalysis , polymer , layer (electronics) , engineering
Abstract Lignocellulosic substrates such as wood have been found to have a marked modifying influence on both lower‐temperature and higher‐temperature zones of TTT and CHT diagrams during hardening of formaldehyde‐based polycondensates. While the modifying influence of the substrate has been described, the modifying influence of some of the most important manufacturing parameters of the resins on the CHT diagram, not having been previously investigated, are explored here and clear trends are shown. In the case of melamine–urea–formaldehyde (MUF) resins for wood adhesives, the molar ratio (M+U):F appear to be the dominant parameter influencing the relative position of gel and vitrification curves in relation to each other. The ratio of melamine to urea does not appear to have any effect on the relative position of the curve, lacking any clear trend, at least at the higher (M+U) molar ratio of 1:1.9 used for this series of resins. In the case presented for the first time, the influence of resin manufacturing parameters on CHT curing diagrams was studied in combination with the modifications introduced by the substrate. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2821–2825, 2001