Boiling treatment of ABS and PS plastics for flotation separation

•Boiling treatment was developed to aid plastic separation.•Surface rearrangement of polymer made surface of boiling treated ABS hydrophilic.•Flotation separation of ABS and PS was achieved efficiently.

A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile–butadiene–styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling.

Graphical abstractAs shown in the figure above, surface rearrangement of polymer made surface of boiling treated ABS hydrophilic. Flotation separation of ABS and PS plastics was achieved efficiently combined with boiling treatment.Figure optionsDownload full-size imageDownload as PowerPoint slide