AGING STUDY OF LINSEED OIL RESIN/STYRENE THERMOSETS AND THEIR COMPOSITES WITH WOOD FLOUR

MIRNA A. MOSIEWICKI; OSCAR ROJAS; MARÍA R. SIBAJA; JULIO BORRAJO; MIRTA I. ARANGUREN

POLYMER INTERNATIONAL

Wiley

Lugar: Chichester; Año: 2007 vol. 56 p. 875 - 881

0959-8103

The changes in the properties of new crosslinked polymers based on renewable resources and its derived composites have been monitored along time; its knowledge being necessary to estimate their behavior in final applications. Rigid thermoset polymers prepared by free radical polymerization of resins obtained from linseed oil and styrene and composites reinforced with wood flour, were evaluated in different environmental conditions and at different times after their preparation. The action of atmospheric oxygen on the fatty acid unsaturations produces chemical changes in these polymers, which affect the properties of the cured materials. These changes have been analyzed by FTIR, DMA and mechanical testing. An increase in the modulus with time was observed during exposure of the samples to dry conditions, or humid environments (60% relative humidity), with or without UV irradiation. The reaction with oxygen appears to be accelerated when the materials are subjected to UV irradiation, showing a large effect on the glass transition temperature.