Thermal properties of hybrid lignocellulosic fabric-reinforced polyester matrix composites

The thermal diffusivity, thermal conductivity and specific heat of jute/cotton, sisal/cotton and ramie/cotton hybrid fabric-reinforced unsaturated polyester composites were determined. These properties were measured both parallel and perpendicular to the plane of the fabrics. The results obtained show that higher values were obtained parallel to the plane of the fibers. Sisal/cotton composites show a particular behavior, with thermal properties very close to those of the resin matrix. The thermal properties of the fabrics, i.e. without any resin, were also evaluated and were used to predict the properties of the composites from the theoretical series and parallel model equations. Experimental and theoretical values were compared and discussed. The effect of fabric pre-drying on the thermal properties of the composites was also evaluated. The results show that the drying procedure used did not bring any relevant change in the properties evaluated.