Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins

Shin-ichiro Tohmura; Chung-Yun Hse; Mitsuo Higuchi

Treesearch

Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins

Informally Refereed

Authors:

Shin-ichiro Tohmura, Chung-Yun Hse, Mitsuo Higuchi

Year:

2000

Type:

Scientific Journal

Station:

Southern Research Station

Source:

J Wood Sci. 46:303-309

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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-state ¹³C 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 methyl0l 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-state ¹³C CP/MAS NMR spectra showed that formaldehyde emission from cured UF resins after heating is mainly ascribable to decreased methyl01 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.

Keywords

urea-formaldehyde resin, Formaldehyde-emission, Solid-state 13C CP/MAS NMR, Heat stability

Citation

Tohmura, Shin-ichiro; Hse, Chung-Yun; Higuchi, Mitsuo. 2000. Formaldehyde emission and high-temperature stability of cured urea-formaldehyde resins. J Wood Sci. 46:303-309