- Author
- Zarr, R. R. | Nguyen, T.
- Title
- Effect of Environmental Exposures on the Properties of Polyisocyanurate Foam Insulation: Thermal Conductivity Measurements.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Society of the Plastics Industry of Canada. Long-Term Thermal Performance of Cellular Plastics. 2nd International Workshop. June 5-7, 1991, Ontario, Canada, 1-14 p., 1991
- Keywords
- polyisocyanurate foam | environmental effect | exposure | thermal conductivity | insulation | rigid foams
- Identifiers
- measurements of specimen mass and bulk density
- Abstract
- Measurements of apparent thermal conductivity are presented for specimens of rigid polyisocyanurate (PIR) foam conditioned in one of four environments. Measurements were conducted at 24 deg C and a temperature difference of 22 deg C at monthly intervals for six months using a heat-flow-meter apparatus (ASTM Test Method C 518). Four specimens (nominally 610 by 610 mm) were prepared from one commercial board (nominally 1.2 by 2.4 m) of rigid PIR foam blown with R11 and having permeable organic/inorganic facers. Facers and excess material were removed by sanding the specimens to a thickness of 26.7 ± 0.1 mm. Three specimens were conditioned in the following environments: 1) ambient conditions of 22 deg C and 40% relative humidity (RH); 2) 60 deg C, uncontrolled humidity, and ; 3) sinusiidal cycling from 0 to 60 deg C over 24 hours, uncontrolled humidity. The fourth specimen was immersed under 50 mm of distilled water at 21 deg C for three months and subsequently conditioned for three months at ambient conditions of 22 deg C and 40% RH. For the six month period, the increase in apparent thermal conductivity for the four specimens ranged from 11.5 to 14.2%. Aging curves of thermal conductivity for each specimen are described in the paper.