Thermophysical properties of SiOC nonwoven composite with addition of SiC powder

Manufactured of polycarbosilane (PCS) based SiOC nonwoven composite by polymer infiltration process(PIP) has been done. Nonwoven fiber as a filler was made by solute 1,2 g/mL PCS in toluene/N, N-Dimethylformamide (DMF) with ratio 30/70. Solution of PCS was processed by electrospinning that varied it's processing voltage at 10 kV, 12 kV and 14 kV. Matrix solution's was made by solute 1,2 g/mL PCS in toluene and the composite was done by PIP technique. Composites were varied by addition second phase SiC powder with additions of volume fraction ranged at 13 - 21 %. Characterizations of composites was done such as density measurements, morphology observations, heat capacity measurements and thermal conductivity measurements. The results, showed the value of density measurements were lower than theoretical density of SiC where the highest value at 1,33 g/cm³ was achieved by composite with added by SiC powder and the highest value of open porosity at 39,22 %. The cross sections morphology of composites show the different surface contour level and showed different phases by different greytone gradations. The brightest colour showed the phases that dominated by silicon element. The darken colour sowed the phases that dominated by carbon element and porosity showed by black colour. The value of composites heat capacity trends showed similarity to the SiC crystal heat capacities, but there were phonons excitation that showed existence the amorphous phases and porosity in the composites. The value of heat capacity of composites ranged at 400 - 1300 J/kg.K for measurement temperature ranged at 300 - 700 K. The value of thermal conductivity of composites without addition of SiC powder ranged at 4 - 6 W/m.K, and ranged at 8 - 14 W/m.K for the composites with addition of SiC powder. (author)