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Abstract

Monitoring thermal conductivity changes in thin-sliced cellular plastics has drastically reduced the time required to evaluate the long-term aging of insulating foams. Monitoring the weight changes of closed-cell thin-slices provides data which can be analyzed to determine the effective diffusivity of atmospheric and blowing agent gas components. The effective diffusivity of atmospheric gases are about two orders of magnitude larger than that of permanent insulating blowing agents. This large difference in effective diffusivity allows each gas to be determined independently.

Specimens of polyurethane (PU) and polyurethane modified polyisocyanurate (PUIR) foam were prepared using cyclopentane or n-pentane in the PUIR foams.

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References

Moore, S.E. 1991. "Effect of Polymer Structure on the Long-Term Aging of Rigid Polyurethane Foam," 2nd International Workshop on Long-Term Performance of Cellular Plastics, Niagara-on-the-Lake, Ontario, Canada, June 5-7.

Booth, J.R. 1993. "An Evaluation of the Dow Thermal Performance Prediction Model for a Database of XEPS/CFC-12 Aged Resistivity and Physical Properties ," J. Thermal Insul. and Bldg. Envs., 17:154-170.

Carslaw, H.S. and J.E. Jaeger. 1959. Conduction of Heat in Solids, Second Edition. New York: Oxford University Press, pp.97.

Cuddihy, E.F. and J. Moacanin. 1967. "Diffusion of Gases in Polymeric Foams," J. Cellular Plastics, 3(Feb.):73-80.

Bomberg, M.T. 1990. "Scaling Factors in Aging of Gas-Filled Cellular Plastics," J. Thermal Insulation, 13:149.

Crank, J. and G.S. Park. 1968. "Methods and Measurements," in Diffusion in Polymers, J. Crank and G. S. Park (eds.), London: Academic Press, pp. 1-39.

Christian, J.E. , G.E. Courville , R.S. Graves , R.L. Linkous , D. L. McElroy, F.J. Weaver and D.W. Yarbrough. 1991. "Thermal Measurement of in-situ and Thin-Specimen Aging of Experimental Polyisocyanurate Roof Insulation Foamed with Alternative Blowing Agents," Insulation Materials. Testing and Applications, 2nd Volume, ASTM STP 1116, R. S. Graves and D. C. Wysocki (eds.), Philadelphia: American Society for Testing and Materials, pp. 142-166.

Booth, J.R. , R.S. Graves and D.W. Yarbrough. 1994. "Aging of Thin-Slices of PUIR Foams Manufactured with Alternative Blowing Agents," J. Thermal Insul. and Bldg. Envs., 19:118-131.

Bhattacharjee, D. , P.W. Irwin , J.R. Booth and J.T. Grimes. 1993. "The Acceleration of Foam Aging by Thin Slicing—Some Interpretations and Limitations," J. Thermal Insul. and Bldg. Envs., 16:365-374.

10.

Tye, R.P. 1991. "Literature Search and Recommended Procedures for Determining Aged Thermal Values of Polyisocyanurate and Polyurethane Roof Insulations ," in Improved Thermal Insulation, D. A. Brandreth (ed.), Lancaster, PA: Technomic Publishing Co., Inc.

11.

ASTM C 1303-95. 1995. "Standard Test Method for Estimating the Long-Term Change in the Thermal Resistance of Unfaced Rigid Closed Cell Plastic Foams by Slicing and Scaling under Controlled Laboratory Conditions ," Philadelphia: American Society for Testing and Materials.

12.

Volkert, O. 1995. "Cyclopentane-Blown Rigid Foams for Refrigerators," J. Cellular Plastics, 31:210-216.

The Effective Diffusivity of Cyclopentane and n-Pentane in PU and PUIR Foams by Thin-Slice Gravimetric Analysis

Abstract

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