废弃软质聚氨酯泡沫塑料的碱性水热降解

Alkaline hydrothermal degradation of Waste Flexible Polyurethane Foams

利用连续水热处理装置,开展了废弃软质聚氨酯泡沫塑料的水热降解研究。比较了碳酸钠、氢氧化钠和氢氧化钾3种碱性助剂对水热处理效果的影响。实验结果表明:3种碱性助剂对废弃软质聚氨酯泡沫塑料的水热降解均表现出一定程度的促进作用,其中氢氧化钾和氢氧化钠的促进作用较强,持续时间较长;增加氢氧化钠或氢氧化钾的用量、升高温度,均能够促进废弃软质聚氨酯泡沫塑料的水热降解;在用量相同的条件下,氢氧化钾的促进作用优于氢氧化钠;压力对废弃软质聚氨酯泡沫塑料的水热降解效果影响不明显;氢氧化钾、氢氧化钠可与废弃软质聚氨酯泡沫塑料降解过程中所产生的CO_(2)反应,使其转化为溶解性较好的碳酸盐而转移至水相,还能够促进废弃软质聚氨酯泡沫塑料中某些功能基团的解离,加快某些有机降解产物的进一步分解,从而加快了废弃软质聚氨酯泡沫塑料的降解过程。

The hydrothermal degradation of waste flexible polyurethane foams(WFPF)were studied in a continuous hydrothermal treatment device.The effects of three alkaline additives of KOH,NaOH and Na_(2)CO_(3)on hydrothermal treatment were compared.The experimental results indicate that:The three alkaline additives exhibit certain extents of promoting effect on the hydrothermal degradation of WFPF,among which KOH and NaOH have a strong promoting effect and a long duration;The increase of KOH or NaOH content,or the rise of temperature can promote the hydrothermal degradation of WFPF;Under the condition of same amount,the promoting effect of KOH is better than that of NaOH;Pressure has less effect on the hydrothermal degradation of WFPF;KOH and NaOH can reacte with CO_(2)generated in the WFPF degradation to convert it into carbonate with good solubility and transfer it to the aqueous phase,simultaneously,they can also promote the dissociation of some functional groups in WFPF,accelerate the further decomposition of some organic degradation products,and speed up the degradation process of WFPF.