Insulation Materials Series- fourth installation Polyisocyanurate

Also referred to as polyiso, it is a thermoset plastic produced as a foam. Polyisocyanurate is comprised of similar materials to polyurethane. A reaction of methylene diphenyl diisocyanate?(MDI) and polyol along with a few catalysts takes place at a high temperature. The MDI will react with itself first producing a stiff ring molecule (a tri-isocyanate isocyanurate compound). The remaining MDI and tri-isocyanate react with polyol to form a complex polyurethane isocyanurate polymer, which is then foamed using a blowing agent. This means the isocyanurate, has a combination of strong chemical bonds and has strong molecular structure. Polyisocyanurate has many ingredients in common with polyurethane, however due to the proportion of these ingredients, it is more chemically and thermally stable.

Polyurethane was accidentally produced in 1954. 13 years later, scientists had improved the formula to make it thermally and dimensionally more stable, as well as flame and chemical resistant. The material was then introduced to the building materials market in the late 1970’s.

Insulation Components Inc. Polyisocyanurate Insulated iShields prevent pipe insulation crushing and maintain insulation integrity at pipe hanger locations.

Some product data; Used on low and mid temperature plumbing and HVAC piping. - commonly installed on lines such as: domestic hot and cold water, chilled water, hot water heating, condenser water, and low-pressure steam. - Provide a full 360 degrees of high density (HD) insulation and ASJ plus (All Service Jacket) vapor barrier. - ASJ with SSL for quick and positive installation on piping. - Available in standard lengths from 6“to 36" long to meet MSS SP-58 point load requirements for a wide range of hanger types and spans.

Sources: IKO Global, Wikipedia, Johns Manville, Insulation Components data sheet