Optimizing the conditions of quantitative13C-NMR spectroscopy analysis for phenol-formaldehyde resol resins

Luukko, Petra; Alvila, Leila; Holopainen, Timo; Rainio, Jouni; Pakkanen, Tuula T.

doi:10.1002/(sici)1097-4628(19980829)69:9<1805::aid-app15>3.0.co;2-k

Cited by 19 publications

(22 citation statements)

References 2 publications

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“…Figure provides the 13 C‐NMR spectrum of phenolic resin, in which the absorption peak at 39.5 ppm corresponds to the solvent DMSO‐ d 6. Literature values of the 13 C chemical shift of phenolic resin are provided in Table . As indicated by Fig.…”

Section: Resultsmentioning

confidence: 99%

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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Section: Resultsmentioning

confidence: 99%

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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“…Cr(acac) 3 [tris(acetylacetonate)chromium(III), 97%; Aldrich, Milwaukee, WI] was the relaxation agent for shortening the spin-lattice relaxation time, enhancing sensitivity, and maintaining the quantitative NMR spectra. 14,15 The liquid NMR samples were prepared in a 5-mm NMR tube (Wilmad, royal imperial grade) by dissolving approximately 350 mL of liquid resin in about 70 mL of pure DMSO-d 6 and 280 mL of 50 mM Cr(acac) 3 / DMSO-d 6 mixture. The concentration of the relaxation agent in the NMR sample was optimal, 20 mM.…”

Section: Nmr Experimentsmentioning

confidence: 99%

Novel two‐stage phenol–formaldehyde resol resin synthesis

Monni¹,

Alvila²,

Rainio³

et al. 2006

J of Applied Polymer Sci

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The synthesis of phenol-formaldehyde resol resins was carried out in two stages to facilitate the start of a conventional batch process. In the first stage, the starting material solution was preprocessed in a continuous-flow stirredtank reactor with a 5-min residence time. In the second stage, synthesis was continued in a batch reactor. Samples were analyzed by titrimetric methods, gas chromatography, nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. Most of the starting materials were consumed in the preprocessing reactor, which allowed better control of the reactivity of the prepolymer solution in the second stage. The methylolation and condensation reactions proceeded steadily during the production process in the batch reactor. The results of the study indicated that dividing a conventional one-stage batch process into two stages could facilitate the control of the initial stages of resol production.

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“…The ANOVA F-test indicates the dependence of the dependent variables with the independent variables, P level indicates the statistical significance of the correlation, and t values indicate the strength of the correlation between dependent variable and independent variables (Table VI). The F-test results for relations of the amount of para methylol phenols with the F/P molar ratio and the condensation viscosity are high, 27.162 and 24.207, respectively, indicating a clear dependence of para methylol phenols on the F/P molar ratio and the condensation viscosity. However, for the OH/P molar ratio, the F-test result is very low, 0.108.…”

Section: Statistical Analysis Resultsmentioning

confidence: 92%

Effect of F/P and OH/P molar ratios and condensation viscosity on the structure of phenol‐formaldehyde resol resins for overlays—A statistical study

Holopainen¹,

Alvila

Savolainen

et al. 2004

J of Applied Polymer Sci

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ABSTRACT:A two-level full factorial experimental design with three variables, formaldehyde-to-phenol (F/P) molar ratio, hydroxyl-to-phenol (OH/P) molar ratio, and condensation viscosity was implemented to determine the effect of the variables on the structure of phenol-formaldehyde resol resins for paper overlay impregnation. Ten resins were prepared with F/P molar ratios between 1.9 and 2.3, OH/P molar ratios between 0.09 and 0.13, and condensation viscosities between 60 and 180 mPa s. The effect of these three independent variables on the chemical structure was analyzed by 13 C-NMR spectroscopy, on the molecular weight distribution by gel permeation chromatography, and on the reactivity by differential scanning calorimetry.

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Optimizing the conditions of quantitative13C-NMR spectroscopy analysis for phenol-formaldehyde resol resins

Cited by 19 publications

References 2 publications

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

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

Novel two‐stage phenol–formaldehyde resol resin synthesis

Effect of F/P and OH/P molar ratios and condensation viscosity on the structure of phenol‐formaldehyde resol resins for overlays—A statistical study

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