Separation and Solvent Based Material Recycling of Polycarbonate from Electronic Waste

作者：Evan Yu, Kalsoom Jan, Wan‐Ting Chen · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2023 · DOI：10.1021/acssuschemeng.3c03152 · 被引用次数：31 · 研究领域：Recycling and Waste Management Techniques、Microplastics and Plastic Pollution、Extraction and Separation Processes

Electronic waste is an ever growing waste stream across the globe containing components from a variety of electronics including computers, cell phones, televisions, and other household appliances. Unfortunately, current recycling rates for the waste stream are less than 20%. To help improve electronic waste recycling rates and protect the environment, this research focused on two major concepts: (1) density separation to effectively separate plastics found in electronic waste and (2) identification of safer solvents and antisolvents for material recycling of polycarbonate (PC) from electronic waste plastics utilizing the Hansen Solubility Parameter (HSP) theory. This study showed that density separation using salt water could effectively sort heterogeneous polymers present in electronic waste, with PC more easily separated from the waste than other polymers. The solubility of waste PC was then measured and quantified using HSP theory. Dissolution screening results indicated that N -methylpyrrolidone (NMP) and dichloromethane (DCM) can fully dissolve waste PC. Antisolvent screening indicated water as an effective antisolvent to be used with NMP, with a precipitated yield of around 90%. Elemental analysis also showed that an antisolvent such as water can remove phosphorus-based flame retardants from waste PC by around 30 wt %. However, polymeric property analyses showed that the recovered material appears to degrade during precipitation processing using water, which may signify...