ABSTRACT:
Cellular glass technology with respect to solar energy applications is briefly reviewed and current applications and related studies are discussed. Using the evaluation criteria of water vapor permeability and conformability, a protective butyl rubber/silicone conformal coating system was selected for use on Foamglas® substrates in a freeze/thaw environment. The selection of a specific freeze/thaw cycle which closely models field conditions is discussed. A sampling plan is described which allows independent evaluation of the effects of conformal coatings, cycle number and location within the environmental chamber. The results of visual examination, measurement of density, modulus of rupture and Young's modulus are reported. Based upon statistical evaluation of the experimental results, it was concluded that no degradation in mechanical properties of either coated or uncoated Foamglas® occurred within the duration of the test (53 freeze/thaw cycles). Recommendations are made for further work in the area of the effect of selected coatings on cellular glass in the freeze/thaw environment.