Yellowing reaction in encapsulant of photovoltaic modules
- Japan Quality Assurance Organization, Hamamatsu, Shizuoka (Japan). Solar Techno Center
To clarify the mechanism of the yellowing reaction in encapsulant used for photovoltaic (PV) modules, a low molecular weight substance in EVA (Ethylene vinyl acetate) under accelerated weathering test (Dew cycle test, 1000 hours) with yellow change and virgin EVA were extracted with methanol. Extracts were chemically analyzed by GCIR (Gas Chromatography Infrared-Ray spectroscopic analysis), GC-AED (Gas Chromatography Atomic Emission Detector), and FDMS (Field Desorption Mass Spectroscopy). The conditions of this accelerated test were based on JIS-K9117. The analysis results showed that 2,6-di-t-butyl-4-methyl phenol of antioxidant and 2-hydroxy-4-octoxy-benzophenone of UV absorbent were consumed after the weathering test and that 3,5-di-t-butyl-4-hydroxy-benzaldehyde having yellow color was newly produced. A mechanism of the yellowing reaction in encapsulant was presented here that 2,6-di-t-N-O radical from Bis-2,2,6,6-tetramethyl-4-piperidinyl sebacate to produce 3,5 di-t-butyl-4-hydroxy benzaldehyde.
- OSTI ID:
- 304469
- Report Number(s):
- CONF-970953-; TRN: IM9905%%161
- Resource Relation:
- Conference: 26. IEEE photovoltaic specialists conference, Anaheim, CA (United States), 29 Sep - 3 Oct 1997; Other Information: PBD: 1997; Related Information: Is Part Of Conference record of the twenty sixth IEEE photovoltaic specialists conference -- 1997; PB: 1477 p.
- Country of Publication:
- United States
- Language:
- English
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