Alcatrão ou creosoto de eucalipto na produção de adesivos fenólicos para colagem de madeira


Autoria(s): Pimenta,Alexandre Santos; Vital,Benedito Rocha; Fujiwara,Fred Yukio
Data(s)

01/08/1997

Resumo

This study has shown that Eucalyptus tar and creosote can be used in phenolic adhesive formulations (resols) for wood products bonding. Some adhesives were prepared substituting 0; 17.7; 35.0 and 67.0% of the phenol by anhydrous tar and 0; 15.0 e 28.5% by creosote. In gluing Brazilian pine veneers, eucalypt tar and creosote based adhesives required longer pressing times for curing than conventional phenol-formaldehyde adhesives. By using 13C NMR, the number of carbons in side chains and hydroxyl, carbonyl, carboxyl and methoxyl groups related to 100 aromatic rings could be estimated in tar and creosote. In creosote, after reaction with excess formaldehyde in alkaline medium, only 0,28 hydroxymethyl groups was detected per phenolic ring. This low amount of hydroxymethylation explains the lack of reactivity in curing observed when creosote was introduced in a standard adhesive formulation.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40421997000400005

Idioma(s)

pt

Publicador

Sociedade Brasileira de Química

Fonte

Química Nova v.20 n.4 1997

Palavras-Chave #tar and creosote from eucalypt #wood adhesives #13C-NMR spectroscopy
Tipo

journal article