Effects of Humidity and Elevated Temperature on the Density and Thermal Conductivity of a Rigid Polyisocyanurate Foam Co-Blown With CCI3F and CO2.
Effects of Humidity and Elevated Temperature on the
Density and Thermal Conductivity of a Rigid
Polyisocyanurate Foam Co-Blown With CCI3F and CO2.
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
Journal of Thermal Insulation and Building Environments,
Vol. 17, 330-350, April 1994.
polyisocyanurate foam; humidity; temperature; density
effects; thermal conductivity; rigid foam;
trichlorofluoromethane; carbon dioxide
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: 
60 deg C and <10% RH;  60 deg C and 40% RH;  60
deg C and 60% RH; and,  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.