| 摘要 |
An improved method of recycling polystyrene foam involving collapsing the polystyrene foam in a solvent/cosolvent system without dissolving the polystyrene and then separating and recovering the softened polystyrene typically floating of the liquid solvent system phase. The solvent system useful for collapsing foamed polystyrene comprises a dibasic organic acid ester solvent selected from the group consisting of dialkyl adipate, dialkyl glutarate, dialkyl succinate and mixtures thereof and a cosolvent selected from the group consisting of ethylene glycol, propylene glycol, propylene carbonate, dimethyl sulfoxide, diacetone alcohol, isopropyl alcohol, and mixtures thereof wherein the cosolvent is present in said solvent/cosolvent system from at least 10 weight percent up to 40 weight percent. Such a process is particularly useful for isolating and recovering both polystyrene and PET in that PET is denser than the liquid solvent system phase and is soluble in the liquid solvent phase at elevated temperatures. |
