Abstract Ethylene-vinyl acetate (EVA), a copolymer of ethylene and vinyl acetate, is widely used as an encapsulant in the silicon solar module to bind the different layers together and protecting the solar cells from over stressing, cracking, and environmental effects. In this work, EVA has been recovered successfully from the used silicon solar module by thermal treatment at 170 °C temperature and the application of mechanical force. The established process is completely environment-friendly, as the EVA layer was recovered without any degradation and emission of any gas. The presence of extracted EVA and its chemical composition was confirmed from FTIR and EDAX measurements. It was observed from Thermogravimetry (TGA) and Differential thermogravimetry (DTG) that thermal degradation of EVA was a two-step process, and also the rate of reaction was fast in an air environment as compared to nitrogen environment. The extracted EVA is thermally stable until 215 °C in the air environment. From Differential scanning calorimetry (DSC) analysis, two endothermic peaks were observed at temperature 37 °C and 55 °C, which may be due to beginning of melting of vinyl acetate and ethylene crystallites respectively in air and nitrogen environment. From UV–visible spectroscopy, it was found that above 500 nm, the extracted EVA is transparent. After examined through the various characterization, it has been observed that extracted EVA shows quite similar properties as that of commercially available EVA. Therefore, the recovered EVA may be used in the encapsulation of solar modules and other applications in packaging and textile industries.

中文翻译：

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从硅太阳能组件废料中提取 EVA 的结构组成和热稳定性

摘要 乙烯-醋酸乙烯酯 (EVA) 是乙烯和醋酸乙烯酯的共聚物，广泛用作硅太阳能组件中的密封剂，将不同层粘合在一起，保护太阳能电池免受过应力、开裂和环境影响。在这项工作中，通过在 170°C 温度下进行热处理并施加机械力，已成功地从使用过的硅太阳能模块中回收 EVA。既定的过程是完全环保的，因为 EVA 层在没有任何降解和任何气体排放的情况下被回收。FTIR 和 EDAX 测量证实了提取的 EVA 及其化学成分的存在。从热重法 (TGA) 和差示热重法 (DTG) 观察到，EVA 的热降解是一个两步过程，并且与氮气环境相比，在空气环境中反应速度快。提取的 EVA 在空气环境中热稳定直到 215 °C。从差示扫描量热法 (DSC) 分析，在温度 37 °C 和 55 °C 处观察到两个吸热峰，这可能是由于乙酸乙烯酯和乙烯微晶分别在空气和氮气环境中开始熔化。从紫外可见光谱发现，在 500 nm 以上，提取的 EVA 是透明的。在通过各种表征检查后，已经观察到提取的 EVA 显示出与市售 EVA 非常相似的特性。因此，回收的 EVA 可用于太阳能模块的封装以及包装和纺织行业的其他应用。