Low formaldehyde emission urea-formaldehyde resins modified by 2,4,6-trimethylolphenate and physical properties of its impregnated papers

Abstract

The objective of this study is using 2,4,6-trimethylolphenate (TMP) as modifier to prepare stable TMP-Urea-Formaldehyde resins (TMPUF) with low formaldehyde emission and using TMPUF to improve mechanical properties and water resistance of the common filter paper. The prepared TMPUF was characterized by IR, DSC and POM. The results indicated that as the mass ratio of TMP/U was increased, the free formaldehyde concentration of the TMP modified UF resins was decreased. Curing temperature of TMPUF was increasing with the decreasing of free low formaldehyde and POM analysis showed that the crystalline structure of TMPUF is destroyed with the adding of TMP. In addition, mechanical properties, thermal stability and water absorption of TMUF impregnated papers have been studied. The results showed that both mechanical properties and water absorption of TMPUF impregnated papers can be improved in the experimental range. However, all TMPUF impregnated paper shows little difference in thermal stability. These results indicated that TMP as a kind of phenol-formaldehyde intermediate is a useful alternative to formaldehyde and phenol to reduce environmental pollution. This work provides a method of preparing stable TMPUF adhesives with low formaldehyde emission used for wood adhesives and paper impregnating applications.