BFRL ICON Effects of Humidity and Elevated Temperature on the Density and Thermal Conductivity of a Rigid Polyisocyanurate Foam Co-Blown With CCI3F and CO2.

pdf icon Effects of Humidity and Elevated Temperature on the Density and Thermal Conductivity of a Rigid Polyisocyanurate Foam Co-Blown With CCI3F and CO2. (858 K)
Zarr, R. R.; Nguyen, T.

Society of the Plastics Industry of Canada's. Workshop on Long-Term Performance of Cellular Plastics, 3rd International. October 4-6, 1993, Ontario, Canada, 1-21 pp, 1993.

Journal of Thermal Insulation and Building Environments, Vol. 17, 330-350, April 1994.

Keywords:

polyisocyanurate foam; humidity; temperature; density effects; thermal conductivity; rigid foam; trichlorofluoromethane; carbon dioxide

Abstract:

Measurements of density and apparent thermal conductivity are presented for specimens of rigid polyisocyanurate (PIR) foam cut from a commercial insulation co-blown with trichlorofluoromethane (CCI3F) and carbon dioxide (CO2). Eight specimens, nominally 580 by 580 mm, were prepared from two boards (1.2 by 2.4 m by 50 mm) of foam laminated with permeable facers. Facers and excess foam were removed by sanding the specimens to a thickness of about 27 mm. Four specimens were placed in ambient conditions of 22 deg C and 40% relative humidity (RH). The other four specimens were each placed in one of the following environments: [1] 60 deg C and <10% RH; [2] 60 deg C and 40% RH; [3] 60 deg C and 60% RH; and, [4] 60 deg C and 75% RH. Measurements of apparent thermal conductivity were conducted at 24 deg C and a temperature difference of 22 deg C using a heat-flow-meter apparatus. Measurements were conducted over a period of 372 days at approximately 50-day intervals. Curves of specimen mass, volume, density, and thermal conductivity versus time are presented and the implications of changes in these properties are discussed.


Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899