Permeation Studies of CFC Alternative Blowing Agents for Rigid Polyurethane Foams

In order to evaluate the migration characteristics of insulating gases and vapors, a method was developed to study the permeation characteristics of the blowing agents through films made from the same materials used to make foams. This paper describes a method for measuring the permeation characteristics through films that represent the foam polymer and summarizes data on the permeation characteristics for two polyisocyanurate polymers. These films are made by using commercial formulations without blowing agents. The blowing agents evaluated were: HCFC-22, HCFC-123, HCFC-141b, HFC-134a, HFC-152a, nitrogen (as an air model), and CFC-11 as a control