Abstract:
The role of surfactants (wetting agents) in effective and efficient flotation separation of naturally hydrophobic plastics, such as polyvinyl chloride (PVC) and polyacetal (POM) has been investigated in terms of wettability and the physical process involved. Results of experiments have shown that sodium lignin sulfonate was a very effective depressant for PVC and sorbitan monolaurate for POM.The efficient flotation separation has been attributed to the changes which surfactant adsorption causes in the wetting characteristics of the two polymers (selective reduction in hydrophobicity measured as the drop in contact angle).