The addition of opacifiers in foams considerably reduces the radiative thermal conductivity and consequently enhances the insulation performance of the foams. In this work two different methods were developed to calculate the spectral specific extinction coefficient of opacified extruded polystyrene (XPS) foam material. Cell morphology and thermal conductivity of two identical XPS-foams, one opacified with 3 wt% carbon black as opacifier and one without opacifier, were thoroughly characterized. The experimental results were in a good agreement with the theoretical results obtained from two different computing techniques. These methods allow a good prediction of the specific extinction coefficient of arbitrary opacified foam material.
ManaraJ., Arduini-SchusterM., HanssenL., High Temp – High Press, 38, (2009), 259–276.
16.
BurgerT.: Radiative Transfer in Disperse Media – New Procedures in Spectroscopic Infrared Analysis. Phd-thesis, University of Würzburg, Germany (1998).
17.
ManaraJ., KellerM., KrausD., Arduini-SchusterM., Stoffelsin G.G.M., van der MeerT.H., and van SteenhovenA.A., Proceedings 5th European Thermal-Sciences Conference, Eindhoven, Netherlands, (2008), ISBN 978-90-386-1274-4.
18.
SiegelR., HowellJ.R., Thermal Radiation Heat Transfer, Third Edition, Washington (1992).
19.
MehlingH., KuhnJ., ManaraJ., BrandtR., FrickeJ., High Temp – High Press, 33, (2001), 35–42.
20.
MehlingH., Determination of infrared-optical properties and phononic thermal conductivity of nonscattering inorganic and nonmetallic materials., Phd-thesis, University of Würzburg, Germany (2001).
JitianS., Determination of Optical Constants of Polystyrene Films from IR Reflection-Absorption Spectra, Annals XVIII, No. 1, UEM of Resita, (2011), ISSN 1453 – 7397.
24.
KerkerM., LoeblE.M., The scattering of light and other electromagnetic radiation, Academic Press (1969).
25.
Van de HulstH.C., Light scattering by small particles, Dover USA (1981).
26.
GlicksmanL.R., StewardJ.“The measurement of the morphology of closed cell which control the overall thermal conductivity” Insulation Materials: Testing and Applications: third Volume, ASTM STP 1320, American Society for testing and Materials (1997).
27.
Quinn BrewsterM., Thermal radiative transfer and properties, Wiley (1992).
