Abordagem multivariada do comportamento das propriedades físico-químicas e caracterização de adesivos naturais à base de taninos

Abstract

Phenol-formaldehyde and urea-formaldehyde are derived from petroleum and there a huge concern in replacing itscomponents, particularly the toxicity and carcinogenic potential they possess. Tannins are potential substitutes for phenol and furfuryl alcohol and hexamethylenetetramine are described in the literature as binders which do notrelease formaldehyde. Thus, Tannins-furfuryl alcohol adhesives (TAF), Tannin-formaldehydeParaformaldehyde (T-FP) and tannins-Hexamethylenetetramine (TH) were prepared and sampled through multivariate analysis,using full factorial design. The results allowed us to understand that relational variables and interactions influence the physicochemical properties of viscosity, gel time, solids content and final pH as these are intrinsically related to the bonding quality; the spectroscopic analysis in the infrared Fourier Transform (FTIR), elemental analysis (CHNS-O) and thermal gravimetric analysis (TGA / DTA) confirmed the formation of adhesives; and finally to dry the glue line shear tests and showed wood failure fitness thereof. So, you can replace the synthetic adhesives for natural materials, and know the most appropriate synthesis conditions for each type of wood.