Investigation of Test Methods, Material Properties, and Processes for Solar-Cell Encapsulants. Twenty-Third Quarterly Progress Report for Period Ending February 12, 1982

摘要

During the past quarter technical investigations concerned the development of advanced cure chemistries for lamination type pottants, the continued evaluation of soil resistant surface treatments, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants. One compound in particular, designated Lupersol - TBEC was found to be unusually effective in promoting the rapid cure of both these materials. Formulation of these resins with TBEC resulted in compositions of very high gel content, lower temperatures of activation, and much lower cure times, even in the ethylene/methyl acrylate polymer that is more difficult to cure. An experimental program continued to determine the effectiveness of soil resistant coatings. These treatments have been applied to Sunadex glass, Tedlar and oriented acrylic film. The treatments are based on silicone, acrylic, and fluorosilane chemistries. After one year of outdoor exposure, the most effective treatment of Sunadex glass appears to be a fluorosilane designated L-1668, and for both the organic films a silane modified adduct of perfluoric acid gave the best results. After one year of time there is evidence that the treatments are slowly being lost and consequently a maintenance schedule may be required to maintain effectiveness over long periods of time. An accelerated aging test program is underway for the dual purpose of generating practical and empirical data relating to the service life of candidate encapsulation materials, and to provide data that may be useful in a predictive type of analysis. (ERA citation 07:046197)