Moisture dependence of the properties of composites made from tung oil based polyurethane and wood flour

M. A. MOSIEWICKI; U. CASADO; N. E. MARCOVICH; M. I. ARANGUEN

JOURNAL OF POLYMER RESEARCH

SPRINGER

Año: 2012 vol. 19 p. 1 - 8

1022-9760

Natural composites prepared from a polyurethane(PU) based on tung oil and different percentages of woodflour (WF) or microcellulose (MC) were exposed to humid environments and the resulting changes of their properties were evaluated. The equilibrium moisture content of the composites increased with the wood flour percentage. Dy- namic mechanical tests performed during temperature scans revealed the changes resulting from moisture absorption on the main transition temperature of the matrix as well as on the storage modulus. The tensile mechanical properties of the materials were also strongly affected by moisture. The different degree of dispersion achieved during the incorpo- ration of WF and MC into the matrix was considered the main reason for the different effect of each filler on the thermal and mechanical properties of the resulting composites.