Southern Research Station

Title: Analysis of curing process and thermal properties of phenol-urea-formaldehyde cocondensed resins

Author: Tomita, Bunchiro; Ohyama, Masahiko; Itoh, Atsushi; Doi, Kiyoto; Hse, Chung-Yun

Date: 1994

Source: Mokuzai Gakkaishi 40(2):170-175

Description: The curing processes of resols, urea-formaldehyde (UF) resins, their mechanical blends, and phenol-urea cocondensed resins, as well as the reaction of 2,4,6-trimethylolphenol with urea were investiiated with the torsional braid analysis method. The thermal stabilities of these resins after curing also were compared. The results were as follows: (1) In the curing process of the mechanical blends under acidic conditions, it was found that the self-condensation of UF resins dominates in the initial stages, and that the curing of phenolic resin is apt to be incomplete. In alkaline curing, the blended resins require higher curing temperatures than resol, and their heat-resistances after curing generally were poor. (2) It was found that the reaction of trimethylolphenol with urea involved two stages. It was suggested that the first stage at lower temperatures is attributed to the reaction of p-methylol groups with urea residue, and that the second stage at higher temperatures is due to the reaction of o-methylol groups and urea residue. This mixture gave a resin having a great heat-resistance after completion of the reaction. (3) The curing process of the cocondensed resins also involved two stages. It was concluded that alkaline curing is better than acidic curing for these resins, and also that the heat-resistances of the cocondensed resins are superior to those of the mechanical blended resins.

Keywords: Cocondensation, phenol-urea-formaldehyde, curing process, thermal stability

View and Print this Publication (1.0 MB)

Publication Notes: 

• We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
• This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

 Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

Citation

Tomita, Bunchiro; Ohyama, Masahiko; Itoh, Atsushi; Doi, Kiyoto; Hse, Chung-Yun  1994.  Analysis of curing process and thermal properties of phenol-urea-formaldehyde cocondensed resins.   Mokuzai Gakkaishi 40(2):170-175