| 摘要 |
<p>A process for recovering polyamide from a polyamide-containing waste comprises contacting the polyamide-containing waste with a betainium-based ionic liquid to dissolve polyamide from the polyamide-containing waste. Dissolved polyamide is contacted with a polar solvent to cause precipitation of polyamide and precipitated polyamide is recovered. The polyamide may comprise polycaprolactam and the betainium-based ionic liquid may comprise betainium bis(trifluoromethylsulfonyl)imide. Preferably the polar solvent is aqueous and the polyamide-containing waste is electronic, automotive or carpet waste. The precipitated polyamide may be extracted from the polar solvent by filtration. Advantageously the process recovers polyamides with high purity and achieves a high recovery rate with high selectivity when applied to wastes of mixed polymers.</p> |
