Investigation of Test Methods, Material Properties, and Processes for Solar Cell Encapsulants. Seventeenth Quarterly Progress Report, May 12-August 12, 1980

摘要

The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Development efforts have emphasized the reformulation of polybutyl acrylate, a liquid pottant used in the casting encapsulation process. This material has been modified to yield a composition with much faster cure at lower temperatures. Minimodules have been successfully prepared from this low cost compound and are currently being evaluated by thermal/humidity cycling. Differential thermal analysis (DTA) was used for the examination of thermal stability in some of the pottant compounds of current interest. This method was useful in determining the temperatures at which oxidative or pyrolysis reactions resulted in degradation of the polymers. All the candidate pottants showed degradation onsets of over 200 exp 0 C. The effectiveness of a new primer was determined during this period. This formulation was similar to the silane coupling agent used in past experimentation but was modified with a peroxide to enhance the activity. Excellent bound strengths were obtained to glass, and mild steel that were resistant to immersion in boiling water. EVA to low iron glass gave an average bond strength of 35 lbs per inch of width. This new primer was also evaluated for the corrosion protection that could be provided to metal surfaces when primed and encapsulated in EVA. (ERA citation 06:010495)