Thermal and Mechanical Properties of Woodflour/Tanin Adhesive Composites

MOSIEWICKI, MIRNA; ARANGUREN, MIRTA I.; BORRAJO, JULIO

JOURNAL OF APPLIED POLYMER SCIENCE

Año: 2004 vol. 91 p. 3074 - 3082

0021-8995

ABSTRACT: Composite materials formulated with a natural polyphenolic matrix (commercial tannin adhesive made from quebracho tannin extract), pine woodflour as reinforcing material, and hexamethylenetetramine as hardener were prepared and tested. Scanning electron microscopy of fractured samples was used to analyze the efficiency of the wetting and adhesion of the filler to the surrounding matrix. Thermogravimetric analysis was used in the thermal characterization of the woodflour and the tannin extract. Flexural, compression, and dynamic-mechanical tests were performed on composites to study the relationship of the filler content and particle size with the composite final properties. Moreover, the influence of the moisture content on the physical and mechanical properties of the different composites was analyzed. Results indicated that the mechanical properties were severely affected by the absorbed moisture. Key words: tannin adhesives; woodflour composites; microstructure; thermal properties; mechanical properties