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Factors Influencing the Aging of Rigid Polyurethane Foam

The aging of rigid polyurethane insulation foam is discussed in terms of the basic phenomena involved. Calculated aging curves are presented to illustrate the significance of the FC-11, N2, and O2 diffusion coefficients and initial fluorocarbon pressure on aging behavior. Experimental data are given showing the wide range of aging behavior found with commercial foams, and possible improvements in retarding aging are indicated.