Open AccessStatistical screening analysis of the chemical composition and kinetic study of phenol-formaldehyde resins synthesized in the presence of polyamines as co-catalysts
Author(s) -
Magdalena Cygan,
M. Szemień,
Stanisław Krompiec
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0195069
Subject(s) - diethylenetriamine , phenol , formaldehyde , catalysis , chemistry , trimethylamine , hydroxymethyl , organic chemistry , nuclear chemistry , ammonia , triethylamine
The physico-chemical and application properties of phenol-formaldehyde resins used in the production of laminated plastics depend on such factors as: type and amount of catalyst, formaldehyde-to-phenol mole ratio, temperature and time of the synthesis process. The special impact on the reaction mechanism and kinetics, e.g. on the formation of mono-, di- and trihydroxymethyl derivatives of phenol (PhOH) is a consequence of the type and amount of the catalyst. This paper presents the results of optimisation research of resol resin synthesis catalysed by trimethylamine (TEA) carried out according to 3 2 experimental design. The aim of the research was to determine the synthesis conditions under which it is possible to achieve products with reduced content of unconverted formaldehyde (CH 2 O), phenol and its hydroxymetyl derivatives, while maintaining the required physico-chemical properties. The process employing selected polyamines as well as TEA together with polyamine co-catalysts i.e. diethylenetriamine (DETA) and triethylenetetraamine (TETA) was also studied. The results were compared with those of the resins which were synthesised with the use of classic catalysts–ammonia (NH 3 ) and triethylamine for which the content of CH 2 O, PhOH and its hydroxymethyl derivatives was respectively: NH3—5.13% and 46.27%, TEA—0.33% and 52.41%. In the case DETA was added, the content of phenol and its hydroxymethyl derivatives could be reduced by 52.49% in relation to the resin obtained with the use of TEA and by 46.19% in relation to the resin obtained with the use of ammonia. The formaldehyde content was reduced by 78.79% and 98.64%, respectively. When TETA was added as a co-catalyst, the content of phenol and its derivatives was reduced by 48.04% versus triethylamine-catalysed resin and by 41.15% versus ammonia-catalysed material. The reduction in formaldehyde content reached 84.85% and 99.03%, respectively. The results of kinetic study were also presented, the prediction accuracy of the proposed kinetic model is more than 98% for all the catalysts in the state variable space. Polyamine co-catalysts gave much higher rate constants (0.50 and 0.45 for TETA and DETA, respectively).