The nylon 6 (PA6)/polyurethane (PU) debris produced during the sanding process would result in a serious resource waste and environmental hazard if disposed of inappropriately. Therefore, this study proposed a simple process for separating and recycling PA6 and PU components of PA6/PU debris. Results revealed that the instantaneous dissolution of PU in N,N-dimethylformamide was independent of temperature and time but related to the quantity of the solvent. Further investigation showed that 43.2% of waste PA6/PU debris was dissolved at room temperature, with pulp density of 10% and within 10 minutes, indicating that PA6 and PU could be quickly separated from the waste PA6/PU debris. In addition, proton nuclear magnetic resonance indicated that the dissolved PU could be recovered by selective precipitation-stripping using an equal amount of deionized water. Moreover, the chemical structure analysis disclosed that the PU in PA6/PU debris should be polyether PU synthesized by reacting with methylene diphenyl diisocyanate and polyether polyols. Besides, the stable chemical structure and thermal properties of separated samples observed from differential scanning calorimetry and thermogravimetry results confirmed that the recycling products could be reused as recycled plastic materials.

中文翻译：

---

从废弃尼龙 6/聚氨酯碎片中分离和回收尼龙 6 和聚氨酯组分的简单工艺

打磨过程中产生的尼龙6（PA6）/聚氨酯（PU）碎屑，如果处理不当，会造成严重的资源浪费和环境危害。因此，本研究提出了一种分离和回收 PA6/PU 碎片中 PA6 和 PU 组分的简单工艺。结果表明，PU在N,N-二甲基甲酰胺中的瞬时溶解与温度和时间无关，但与溶剂量有关。进一步调查表明，43.2%的废PA6/PU碎片在室温下溶解，纸浆密度为10%，在10分钟内，表明PA6和PU可以从废PA6/PU碎片中快速分离。此外，质子核磁共振表明，溶解的 PU 可以通过使用等量的去离子水的选择性沉淀汽提来回收。此外，化学结构分析表明，PA6/PU碎片中的PU应该是与亚甲基二苯基二异氰酸酯和聚醚多元醇反应合成的聚醚PU。此外，从差示扫描量热法和热重法结果观察到的分离样品的稳定化学结构和热性能证实回收产品可以作为再生塑料材料再利用。