Flotation separation of acrylonitrile-butadiene-styrene and polystyrene in WEEE based on oxidation of active sites
Flotation separation of acrylonitrile-butadiene-styrene and polystyrene in WEEE based on oxidation of active sites
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基于活性位点氧化的 WEEE 中丙烯腈-丁二烯-苯乙烯和聚苯乙烯的浮选分离
DOI：
10.1016/j.mineng.2019.106131
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发表时间：
2020
影响因子：
4.8
通讯作者：
Wang Chongqing
中科院分区：
文献类型：
--
作者：
Zhang Yingshuang;Jiang Hongru;Wang Hui;Wang Chongqing
利用接触角、扫描电子显微镜(SEM)、傅立叶变换红外光谱(FT-IR)、高分辨X射线光电子能谱(XPS)和核磁共振(核磁共振)等测试手段，实现了丙烯腈-丁二烯(ABS)和聚苯乙烯(PS)的浮选分离，并进一步阐述了ClO2改性ABS的亲水机理。在氧化过程中，丙烯腈、丁二烯和苯乙烯都参与了表面改性。丁腈(三重键N)被水解成酰胺(双键)和羧基(双键)。羟基的单加成(Single BondOH)在丁二烯和苯乙烯单体中引入了羟基。本工作认为ABS的氧化依赖于ABS表面的活性中心，而不是氧化剂。ABS表面的活性中心是丙烯腈中的氰基、丁二烯中的碳-碳双键和苯乙烯中的α-氢。PS与ABS浮选分离的最佳前处理条件为：温度70℃，ClO2投加量0.5g/L，处理时间60min。ABS和PS的浮选率分别为3.3%和96.4%，柔韧性较好。
This work accomplished flotation separation of acrylonitrile–butadienestyrene (ABS) and polystyrene (PS) as well as further elaborating the mechanism of ABS hydrophilization under a novel modification by ClO2, with the help of contact angles, scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), high-resolution X-ray photoelectron spectroscopy (XPS), and nuclear magnetic resonance (NMR). All acrylonitrile, butadiene, and styrene were involved in a surface modification in the process of oxidation. The nitrile (Ctriple bondN) was hydrolyzed to the amide (Odouble bondCsingle bondNH2) and carboxyl (Odouble bondCsingle bondO). Mono-addition of hydroxyl groups (single bondOH) introduced hydroxyl groups into monomers of butadiene and styrene. This work proposed that ABS oxidation was dependent on the active sites on the ABS surface rather than oxidizing agents. The active sites on the ABS surface were nitrile groups in acrylonitrile, carbon-carbon double bonds in butadiene, and α-hydrogen in styrene. The optimal pretreatment conditions for flotation separation of PS and ABS were the temperature of 70 °C, ClO2dosage of 0.5 g/L, and treatment time of 60 min. The flotation percentage of ABS and PS were 3.3% and 96.4% with outstanding flexibility.