Effects of Sodium Bicarbonate Content and Vulcanization Method on Properties of NBR/PVC Thermal Insulator Foam
In this research sodium bicarbonate (NaHCO3) was introduced to generate carbon dioxide gas (CO2) to the existing nitrogen gas (N2) of elastomeric foam, to lower thermal conductivity (K). Various loadings of NaHCO3 (0 to 60 phr) were added into the azodicarbonamide (AZC)-containing compound and its properties were then determined. Two vulcanization methods, i.e., hot air and infrared (IR), were employed and compared in this study. Results revealed that compound viscosity tended to increase slightly with increasing NaHCO3 content but cure time was delayed. The effect of NaHCO3 content on thermal conductivity depended on the vulcanization method. For hot air method, the thermal conductivity was insignificantly changed with increasing NaHCO3 up to 40 phr whereas it tended to decrease gradually for IR method. At higher NaHCO3 content (60 phr), unexpected increase of thermal conductivity was observed. The water absorption was also determined and foam structures were then used to explain the results.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1057773Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3400
 "Energy Crisis" (online) Available from http://en.wikipedia.org/wiki/energy_crisis
[Accessed from 12/4/2009].
 A. Bahadori and H. B. Vuthaluru, "A simple correlation for estimation of economic thickness of thermal insulation for process piping and equipment," Applied Thermal Engineering, vol. 30, pp. 254-259, August 2009.
 "Thermal Conductivity of Material"
[online] Available from http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
[Accessed from 8/4/2009].
 J.C. Rubio-Avalos, A. Manzano-Ramirez, J.M. Ya├▒ez-Lim├│n, M.E. Contreras-Garcia, E.M. Alonso-Guzman and J. Gonz├ílez-Hern├índez, " Development and characterization of an inorganic foam obtained by using sodium bicarbonate as a gas generator" Construction and Building Materials, vol. 19, pp. 543-549, December 2004.
 D. L. Tomasko, A. Burley, L. Feng, S. Yeh, K. Miyazono, S. Nirmal- Kumar, I. Kusaka and K. Koelling, " Development of CO2 for polymer foam applications" The Journal of Supercritical Fluids, vol. 47, pp. 493- 499, October 2008.
 G. G. Gusavage, H. G. Schirmer and T. A. Hessen, "Foam and process for producing foam using a carbon dioxide blowing agent" US Patent Number 5670552, September 1997.
 R. M. Lapierre and N. J. Leonardi, "Chemical blowing agent compositions" US Patent Number 4769397, September 1988.
 V. Padareva, S. Djoumaliisky, N. Touleshkov and G. Kirov, "Modification of blowing agent system based on sodium bicarbonate with activated natural zeolite" J. of Materials Science Letters, vol. 17, pp. 107-109, September 1997.
 J. R. Schauder and G. Stella, "The unique design latitude of EPDM" Rubber World, pp. 23-27, March 1993.
 "Thermal Conductivity of Sodium Chloride" (online) http://www.almazoptics.com/NaCl.htm (Accessed from 22/6/2010).
 J. H. Lienhard, "A heat transfer text book", Prentice-Hall, Inc, 1987, pp. 4-28.