Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
Environ Sci Technol. 2013 Mar 19;47(6):2654-60. doi: 10.1021/es303264c. Epub 2013 Feb 27.
Improved methods are required for the recycling of waste printed circuit boards (WPCBs). In this study, WPCBs (1-1.5 cm(2)) were separated into their components using dimethyl sulfoxide (DMSO) at 60 °C for 45 min and a metallographic microscope was used to verify their delamination. An increased incubation time of 210 min yielded a complete separation of WPCBs into their components, and copper foils and glass fibers were obtained. The separation time decreased with increasing temperature. When the WPCB size was increased to 2-3 cm(2), the temperature required for complete separation increased to 90 °C. When the temperature was increased to 135 °C, liquid photo solder resists could be removed from the copper foil surfaces. The DMSO was regenerated by rotary decompression evaporation, and residues were obtained. Fourier transform infrared spectroscopy (FT-IR), thermal analysis, nuclear magnetic resonance, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to verify that these residues were brominated epoxy resins. From FT-IR analysis after the dissolution of brominated epoxy resins in DMSO it was deduced that hydrogen bonding may play an important role in the dissolution mechanism. This novel technology offers a method for separating valuable materials and preventing environmental pollution from WPCBs.
需要改进方法来回收废弃印刷电路板 (WPCBs)。在这项研究中，将 WPCBs（1-1.5 cm²）在 60°C 下用二甲基亚砜 (DMSO) 处理 45 分钟，然后使用金相显微镜验证其分层。延长孵育时间至 210 分钟可将 WPCBs 完全分离成其组成部分，并获得铜箔和玻璃纤维。分离时间随温度升高而缩短。当 WPCB 尺寸增加到 2-3 cm² 时，完全分离所需的温度升高到 90°C。当温度升高到 135°C 时，可以从铜箔表面去除液态光致抗蚀剂。通过旋转减压蒸发再生 DMSO，并得到残留物。傅里叶变换红外光谱 (FT-IR)、热分析、核磁共振、扫描电子显微镜和能谱分析用于验证这些残留物是溴化环氧树脂。从溴化环氧树脂在 DMSO 中的溶解后的 FT-IR 分析推断，氢键可能在溶解机制中起重要作用。这项新技术提供了一种分离有价值材料的方法，防止 WPCBs 造成环境污染。
