基于低温等离子体修饰的PET/PVC浮选分离

Flotation Separation of PET/PVC Based on Low Temperature Plasma Modification

采用低温等离子体修饰来优化聚对苯二甲酸乙二醇酯(PET)和聚氯乙烯(PVC)混合废塑料的浮选分离效果,研究电晕功率和暴露时间对分离效果的影响。利用接触角测试仪及X射线光电子能谱仪(XPS)对低温等离子体过程中的修饰机制进行探讨。结果表明:低温等离子体修饰可以有效扩大PET/PVC的可浮性差异,电晕过程中产生的羟基自由基可以通过抽氢反应的途径,在聚合物表面选择性引入含氧官能团。对PET/PVC混合物进行修饰的最优工艺参数为电晕功率600 W、暴露时间5000 ms。在PET/PVC混合废塑料进料验证中,PET/PVC质量比为70/30时,PET的回收率和纯度分别可达94.05%和96.16%。拓宽了废塑料分离的技术思路,有助于促进其资源化处理与处置。

The flotation separation effect of polyethylene terephthalate(PET)and polyvinyl chloride(PVC)mixed waste plastics was optimized by low-temperature plasma modification.The effects of corona power and exposure time on the separation effect were studied.The modification mechanism in low temperature plasma process was discussed by means of the contact angle tester and X-ray photoelectron spectroscopy(XPS).The results show that low temperature plasma modification can effectively expand the difference floatability of PET/PVC.The hydroxyl radicals generated during corona discharge may selectively introduce oxygen-containing functional groups on the polymer surface through hydrogen extraction reaction.The optimal process parameters for PET/PVC mixture are corona power of 600 W and exposure time of 5000 ms.In the feed validation of PET/PVC mixed waste plastics,the recovery and purity of PET can reach 94.05%and 96.16%respectively when the mass ratio of PET/PVC is 70/30.It broadens the technical ideas of waste plastics separation and helps to promote its resource treatment and disposal.