Curing kinetics of amine and sodium hydroxide catalyzed phenol-formaldehyde resins

Gabilondo, Nagore; López, M.; Ramos, J.A.; Echeverría, J. M.; Mondragón, Iñaki

doi:10.1007/s10973-006-7747-3

Cited by 50 publications

(42 citation statements)

References 28 publications

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“…From data obtained applying three different isoconversional methods, it is shown that the Ozawa-Flynn-Wall (OFW) and Friedman (FR) models describe similar evolution of the activation energy with the curing degree (Figures 3-5). By increasing the apparent curing degree to more than 70%, the activation energy showed dependence on α values [30], which is also noticed for the curing process of other thermoset resins [11,30,31] and ascribed to the slower diffusion. The activation energy values are insignificantly influenced by apparent curing degree α, especially in the range from 20 to 70% (Figures 3-5).…”

Section: Resultssupporting

confidence: 57%

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Jovičić

Radičević

Pavličević

et al. 2013

CI&CEQ

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The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol) with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC). The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman). Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min) in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments

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Section: Resultssupporting

confidence: 57%

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Jovičić

Radičević

Pavličević

et al. 2013

CI&CEQ

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“…The DSC curve provides important exothermic reaction information on the resin curing process such as temperature range, heat generation (denoting reaction activity), etc. . Previous studies have indicated that there are generally two exothermic peak values in the DSC curve of the phenolic resin; the first corresponds to methylene bond formation by the reaction between hydroxymethyl functional groups and the phenolic hydroxyl group and to the production of the dibenzyl ether bond from two hydroxymethyl groups, whereas the second peak corresponds to the production of the methylene bond by the dibenzyl ether bond through formaldehyde condensation .…”

Section: Resultsmentioning

confidence: 95%

Effect of formaldehyde/phenol ratio (F/P) on the properties of phenolic resins and foams synthesized at room temperature

Zhao

Cheng

2014

Polymer Composites

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Six types of phenolic foaming resins were synthesized at room temperature with different formaldehyde/phenol (F/P) ratios in this study. The effects of F/P ratios on physicochemical characteristics and foaming properties of the resulting resins were analyzed based on viscosity, solids content, hydroxymethyl index, residual monomer content, molecular structure of the foaming resin, flame retardancy, and foam compression strength measurements. The results of the present study indicated that viscosity and solids content of the foaming resins increased with an increase in F/P; the hydroxymethyl index of the resin first increased and then decreased with an increase in F/P, reaching its maximum at F/P = 1.6; the trimer, tetramer, and pentamer contents of the resins increased with an increase in F/P. Nuclear magnetic resonance (13C NMR) spectral analysis indicated that the presence of para/para‐methylene, para‐hydroxymethyl, and ortho‐hydroxymethyl groups in the resin gradually increased with an increase in F/P; the proportions of ortho/ortho‐ and ortho/para‐methylene bonds of the resin increased as F/P was increased. The increase in F/P was demonstrated to be conducive to improving the compression strength, thermal stability, and flame retardancy of the phenolic foam and reducing its peak heat release rate and total smoke release. The morphology of phenolic foams show that the closed cell content in the PF foam increases with the F/P ratio until it reaches a ratio of 1.6. Furthermore, the cell size becomes more uniform. POLYM. COMPOS., 36:1531–1540, 2015. © 2014 Society of Plastics Engineers

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“…However, the lower curing rate and required higher curing temperature compared to other thermosetting adhesives limit the application of PF resins for use in impregnating resins or adhesives [2,3]. Many attempts have been made to accelerate the curing rate or lower the curing temperature, including testing of various catalysts or additives to alter the reaction kinetics, such as carboxylic acid esters [4,5], anhydrides [6], amides [7], carbonate [8], and metallic ions [9]. Additionally, the effects of the condensation condition on the PF resin structure and properties have been well studied by conventional analytical techniques.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Mechanism of Metal-Mediated Polymerization of Phenolic Resins

Zhao

Zhang

et al. 2016

Polymers

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Phenol-formaldehyde (PF) resin is a high performance adhesive, but has not been widely developed due to its slow curing rate and high curing temperature. To accelerate the curing rate and to lower the curing temperature of PF resin, four types of metal-mediated catalysts were employed in the synthesis of PF resin; namely, barium hydroxide (Ba(OH) 2 ), sodium carbonate (Na 2 CO 3 ), lithium hydroxide (LiOH), and zinc acetate ((CH 3 COO) 2 Zn). The cure-acceleration effects of these catalysts on the properties of PF resins were measured, and the chemical structures of the PF resins accelerated with the catalysts were investigated by using Fourier transform infrared (FT-IR) spectroscopy and quantitative liquid carbon-13 nuclear magnetic resonance ( 13 C NMR). The results showed that the accelerated efficiency of these catalysts to PF resin could be ordered in the following sequence: Na 2 CO 3 > (CH 3 COO) 2 Zn > Ba(OH) 2 > LiOH. The catalysts (CH 3 COO) 2 Zn and Na 2 CO 3 increased the reaction activity of the phenol ortho position and the condensation reaction of ortho methylol. The accelerating mechanism of (CH 3 COO) 2 Zn on PF resin is probably different from that of Na 2 CO 3 , which can be confirmed by the differences in the differential thermogravimetric (DTG) curve and thermogravimetric (TG) data. Compared to the Na 2 CO 3 -accelerated PF resin, the (CH 3 COO) 2 Zn-accelerated PF resin showed different peaks in the DTG curve and higher weight residues. In the synthesis process, the catalyst (CH 3 COO) 2 Zn may form chelating compounds (containing a metal-ligand bond), which can promote the linkage of formaldehyde to the phenolic hydroxyl ortho position.

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Curing kinetics of amine and sodium hydroxide catalyzed phenol-formaldehyde resins

Cited by 50 publications

References 28 publications

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Effect of formaldehyde/phenol ratio (F/P) on the properties of phenolic resins and foams synthesized at room temperature

Synthesis and Mechanism of Metal-Mediated Polymerization of Phenolic Resins

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