- Original Articles
- Open Access
- Published:
Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins
Journal of Wood Science volume 46, pages303–309(2000)
Abstract
A test method for measuring formaldehyde from urea-formaldehyde (UF) resins at high temperature was developed and used to assess the influence of the reaction pH on the formaldehyde emission and heat stability of the cured resins. Additionally, solid-state13C CP/MAS nuclear magnetic resonance (NMR) techniques were used to investigate the structure of cured UF resins before and after high temperature heating. Formaldehyde emissions during the cure were related to the UF resins' methylol group content. The heat stability of cured UF resins synthesized under strongly acidic conditions was much higher than that of the other resins, which were prepared in weakly acidic and alkaline media. Solid-state13C CP/MAS NMR spectra showed that formaldehyde emission from cured UF resins after heating is mainly ascribable to decreased methylol groups and dimethylene ether linkages. Significantly, it was revealed that uron structures characteristically found in the cured UF resin synthesized under strongly acidic medium indicated high heat stability.
References
- 1.
Ko K (1976) How to control pollution of formaldehyde for formaldehyde series thermosetting resin adhesives (in Japanese). Settyaku Kyokaishi 12:160–166
- 2.
Tomita B (1980) How chemical structure of UF resin affects formaldehyde emission (in Japanese). Mokuzai Kogyo 35:193–199
- 3.
McVey D (1982) Great strides forward-formaldehyde emission from the production standpoint. In:16th International particleboard symposium, Washington State University, Pullman, WA, pp 21–34
- 4.
Sundin B (1982) Present status of formaldehyde problems and regulations. In:16th International particleboard symposium, Washington State University, Pullman, WA, pp 3–20
- 5.
Myers GE (1984) How mole ratio of UF resin affects formaldehyde emission and other properties: a literature critique. For Prod J 34(5):35–41
- 6.
Hse C-Y, Xia Z-Y, Tomita B (1994) Effects of reaction pH on properties and performance of urea-formaldehyde resins. Holzforschung 48:527–532
- 7.
Myers GE (1985) Effect of separate additions to furnish or veneer on formaldehyde emission and other properties: a literature review (1960–1984). For Prod J 35(6):57–62
- 8.
Myers GE (1986) Effects of post-manufacture board treatments on formaldehyde emission: a literature review (1960–1984). For Prod J 36(6):41–51
- 9.
DeJong JI, deJonge J (1952) The reaction of urea with formaldehyde. Rec Trav Chim 71:643–660
- 10.
DeJong JI, deJonge J (1952) The formation and decomposition of dimethylolurea. J Rec Trav Chim 71:661–667
- 11.
DeJong JI, deJonge J (1953) The hydrolysis of methylenediurea. Rec Trav Chim 72:202–205
- 12.
Landqvist N (1955) On the reaction between urea and formaldehyde in neutral and alkaline solutions. Acta Chem Scand 9:1471–1476
- 13.
Landqvist N (1955) On the reaction between urea and formaldehyde in neutral and alkaline solutions. Acta Chem Scand 9:1466–1470
- 14.
Crowe GA, Lynch CC (1949) Polarographic urea-formaldehyde kinetic studies. J Am Chem Soc 71:3731–3733
- 15.
Dunn AS (1957) The urea-formaldehyde polycondensatioa. I. Kinetics of the hydrolysis of methoxymethylurea. J Chem Soc 75:1508–1510
- 16.
Smythe LE (1953) Urea-formaldehyde kinetics studies. IV. Reactions of methylenebisureas. J Am Chem Soc 75:1508–1510
- 17.
Dunky M, Lederer K (1982) Studies of molecular weight distributions of urea-formaldehyde resinous glues. Angew Makrowmol Chem 102:199–213
- 18.
Kundin K, Simonson R (1978) Urea-formaldehyde resins. 1. Separation of low molecular weight components in urea-formaldehyde resins by means of liquid chromatography. Angew Makrowmol Chem 68:175–184
- 19.
Ludlam RR, King JG (1984) Size exclusion chromatography of urea formaldehyde resins in dimethylformamide containing lithium chloride. J Appl Polym Sci 29:3863–3872
- 20.
Ebdon JR, Heaton PE, Hucherby TN, O'Rourke WTS (1984) Characterization of urea-formaldehyde and melamineformaldehyde adducts and resins by 15N NMR spectroscopy. Polymer 25:821–825
- 21.
Kopf PW, Wagner ER (1973) Formation and cure of novolacs: NMR study of transient molecules. J Polym Sci Polym Chem Ed 11:939–960
- 22.
Nair BR, Francis DJ (1983) Kinetics and mechanism of ureaformaldehyde reaction. Polymer 24:626–630
- 23.
Slonim IY, Alekseeva SG, Urman YG, Arshava BM, Akselrod BY (1978) Study of equilibriums in the urea-formaldehyde system by carbon-13NMR. Vysokomol Soed 20:1477–1485
- 24.
Tomita B, Hirose Y (1976) Urea-formaldehyde resins: NMR study on base-catalyzed reaction of formaldehyde with urea in deuterium oxide. J Polym Sci Polym Chem Ed 14:387–401
- 25.
Myers GE (1985) Resin hydrolysis and mechanisms of formaldehyde release from bonded wood products. In:Wood adhesives in 1985. FPRS, Madison, WI, pp 119–156
- 26.
Troughton GE (1969) Effect of degree of cure on the acidhydrolysis rates of formaldehyde glue-wood samples. J Inst Wood Sci 4(5):51–56
- 27.
Gu J, Higuchi M, Morita M, Hse C (1995) Synthetic conditions and chemical structures of urea-formaldehyde resins. I. Properties of the resins synthesized by three different procedures. Mokuzai Gakkaishi 41:1115–1121
- 28.
Tomita B, Hatono Y (1978) Urea-rormaldehyde resins. III. Constitutional characterization by13C Fourier transform NMR spectroscopy. J Polym Sci 16:2509–2525
- 29.
Maciel GE, Szeverinyi NM, Early TA, Myers GE (1983)13CNMR studies of solid urea-formaldehyde resins using cross polarization and magic-angle spinning. Macromolecules 16:598–604
- 30.
Chuang I-S, Maciel GE (1992)13C CP/MAS NMR study of the structural dependence of urea-formaldehyde resins on formaldehyde-to-urea molar ratios at different urea concentrations and pH values. Macromolecules 25:3204–3226
- 31.
Chuang I-S, Maciel GE (1994) NMR study of the stabilities of urea-formaldehyde resin components toward hydrolytic treatments. J Appl Polym Sci 52:1637–1651
Author information
Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tohmura, S.i., Hse, C.Y. & Higuchi, M. Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins. J Wood Sci 46, 303–309 (2000). https://doi.org/10.1007/BF00766221
Received:
Accepted:
Published:
Issue Date:
Keywords
- Nuclear Magnetic Resonance
- Nuclear Magnetic Resonance Spectrum
- Formaldehyde Emission
- Nuclear Magnetic Resonance Spectroscopy
- Nuclear Magnetic Resonance Study