Improved Solar-Collector Sealants. Final Report, October 1980-July 1982.

摘要

In a program to evaluate materials for use as sealants and gaskets for flat-plate solar collectors, a total of 91 materials were examined. They included the following types: 10 commercial silicone caulks, 9 commercial fluoroelastomer preformed seals; 1 commercial fluorosilicone preformed seal, 6 commercial EPDM preformed seals, 8 commercial silicone preformed seals, 6 commercial acrylic preformed seals, 1 commercial ethylene-acrylic preformed seal, 1 commercial chlorobutyl preformed seal, 5 experimental silicone preformed seals, and 44 experimental fluorocarbon-silicone preformed seals. Properties measured were tensile strength, modulus, and elongation; compression set at 150 exp 0 C and at -10 exp 0 C; hardness, and weight loss. In addition, the more promising materials were subjected to long-term aging at several temperatures, with periodic measurements of tensile properties, weight loss, and compression set. Rough estimates based on extrapolation of compression set curves suggest a 10 year continuous service temperature of 145 exp 0 C for the best of them. The best of the silicone preformed seal materials gave a continuous 10 year life temperature of 116 exp 0 C, based on compression set, and of 98 exp 0 C, based on tensile strength and elongation. Four other silicones were in the range of 96 to 108 exp 0 C, based on compression set, which is probably the most significant property for this application. The best of the EPDM materials had a continuous 10 year life temperatures of 100 exp 0 C, based on average tensile properties, and 72 exp 0 C based on compression set. The best of the sealant caulks had a continuous 10 year life temperature of 95 exp 0 C, based on an end of life criterion of 3% weight loss. (ERA citation 08:035524)