eesti teaduste
akadeemia kirjastus
SINCE 1952
Proceeding cover
of the estonian academy of sciences
ISSN 1736-7530 (Electronic)
ISSN 1736-6046 (Print)
Impact Factor (2020): 1.045

Structure of phenol-formaldehyde polycondensates; pp. 45–52

Full article in PDF format | doi: 10.3176/proc.2009.1.08

Jane Paju, Tõnis Pehk, Peep Christjanson

Prepolymer resol resins with the molar ratio of phenol/formaldehyde 1/2.4 and different amounts of NaOH were synthesized and characterized using 13C NMR spectra for samples in CD3OD solution. Nearly the full substitution in ortho and para aromatic positions occurred, and quite constant ratios of hydroxymethyl/methylene or op '/pp '-methylene groups were obtained. The content of free formaldehyde strongly depends on the NaOH content in synthesis. The prepolymeric chains end mainly with aromatic rings substituted with two ortho-hydroxymethyl groups. The alkali-dependent content of phenoxide ions causes the downfield shifts of 13C signals for ortho-hydroxymethyl groups from 62.8 ppm to 64.4 ppm and for aromatic carbon bearing the hydroxyl group from 157 ppm to 163 ppm. A comparison with industrial resol resin for the manufacture of plywood is presented.

  1. Gardziella, A., Pilato, L. A., and Knop, A. Phenolic Resins. Springer-Verlag, Berlin, 2000.

  2. Pizzi, A. Advanced Wood Adhesives Technology. Marcel Dekker Inc., New York, 1994.

  3. Christjanson, P. Development of alkylresorcinol (AR) resin adhesives: chemistry of AR resins. In Proceed­ings of the Adhesives Bonded Wood Symposium, Forest Products Society, Madison, USA, 1994, 267–277.

  4. Knop, A. and Pilato, L. A. Phenolic Resins. Springer-Verlag, Berlin, 1985.

  5. Fischer, T. H., Chao, P., Upton, C. G., and Day, A. I. One- and two-dimensional NMR study of resol phenol-formaldehyde prepolymer resins. J. Magn. Reson. Chem., 1995, 33, 717–723.

  6. Grenier-Loustalot, M.-F., Larroque, S., Grenier, P., Leca, J.-P., and Bedel, D. Phenolic resins: 1. Mechanisms and kinetics of phenol and the first polycondensates towards formaldehyde in solution. Polymer, 1994, 35, 3046–3054.

  7. Christjanson, P., Pehk, T., Siimer, K., and Paju, J. Structure of polycondensates from hydroxymethyl­phenols. J. Appl. Polym. Sci., 2008, 107, 1226–1234.

  8. Christjanson, P., Suurpere, A., and Köösel, A. Charac­terization of resorcinol- and phenol-formaldehyde prepolymers by 1H NMR spectroscopy. Oil Shale, 1996, 13, 115–122.

  9. Werstler, D. D. Quantitative 13C n. m. r. characterization of aqueous formaldehyde resins: 1. Phenol-formaldehyde resins. Polymer, 1986, 27, 750–756.

10. Rego, R., Adriaensens, R. A., Carleer, R. A., and Gelan, J. M. Fully quantitative carbon-13 NMR characterization of resol phenol-formaldehyde pre­polymer resins. Polymer, 2004, 45, 33–38.

11. Neiss, G. Solution and solid-state NMR analysis of phenolic resin cure kinetics. Macromol. Symp., 1994, 86, 117–129.

12. Grenier-Loustalot, M.-F., Larroque, S., and Grenier, P. Phenolic resins: 5. Solid-state physicochemical study of resoles with variable F/P ratios. Polymer, 1996, 37, 639–650.

13. Yeddanapally, L. M. and Francis, D. J. Kinetics and mechanism of the alkali catalysed condensation of o- and p-methylol phenols by themselves and with phenol. Makromol. Chem., 1962, 55, 74–86.

14. Francis, D. J. and Yeddanapally, L. M. Kinetics and mechanism of the alkali catalysed addition of form­aldehyde to dihydroxydiphenyl methanes. Makro­mol. Chem., 1968, 119, 17–22.

15. Francis, D. J. and Yeddanapally, L. M. Kinetics and mechanism of the alkali catalysed condensations of di- and trimethylol phenols by themselves and phenol. Makromol. Chem., 1969, 125, 119–125.

16. Christjanson, P., Köösel, A., and Suurpere, A. Evaluation of condensation rate of methylolphenols. Oil Shale, 1998, 15, 374–383.

17. Grenier-Loustalot, M.-F., Larroque, S., Grenier, P., Leca, J.-P., and Bedel, D. Phenolic resins: 4. Self-condensation of methylolphenols in formaldehyde-free media. Polymer, 1996, 37, 955–964.

Back to Issue