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A porous matrix was prepared using low-density sawdust and a metakaolin-based geopolymer paste. The matrix was prepared in order to evaluate its performance as a thermally insulating building envelope. The matrices that had approximately 4 MPa of bi-axial four points flexural strength were prepared in a ratio of geopolymer paste:sawdust of between 1:1 and 1:1.5, and the thermal conductivity of these matrices was between 0.2-0.3 W/m·K.
The effective thermal conductivity and thermal diffusivity were investigated for polyaniline (PANI) composites containing iron and manganese at varying temperatures. Composites were prepared containing 100% Fe, 50% Fe and 50% Mn, and 100% Mn. It was determined that both the effective thermal conductivity and effective thermal diffusivity increased with increasing iron content. The authors attribute this increase to the increase in crosslinking density between the nitrogen in PANI and Fe.
The effective thermal conductivity and thermal diffusivity of polymer composites consisting of phenolformaldehyde matrix and oil palm empty fruit bunch (OPEFB) fibers were determined using the transient plane source method. The polymer composites were treated with one of alkali, silanol, or acetic acid to determine the effects of each treatment on the thermo-physical properties of the composites. The effect of temperature on these properties was also evaluated. It was determined that the effective thermal conductivity and thermal diffusivity of each sample reached a maximum at a temperature close to the glass transition temperature of the composite. The thermo-physical properties were also different depending on what treatment was used on the sample.
Inorganic polymers (geopolymers) with varying chemical compositions were subjected to a number of tests in an effort to demonstrate that varying their chemical composition, as well as curing conditions can allow researchers to create geopolymers that fit specific applications based on their microstructure, thermal conductivity, mechanical strength and reliability, and thermal shrinkage behavior.
ICarbon/liquid-crystal polymer composites were formulated. Composites containing one of three types of carbon filler, composites containing two types of carbon filler, and composites containing all three types of carbon filler were prepared to test not only the effect of each filler on the thermal conductivity of the composite, but also the effect of combining fillers. The anisotropic method on a TPS system was used for the thermal conductivity measurements. was found that all of the composites showed a statistically significant increase in thermal conductivity. Of the samples containing only one type of filler, those containing only synthetic graphite showed the largest increase.
