对苯二甲酸对废旧棉纤维水热碳化的影响
2017-06-05侯文生张美玲史晟郜娟高立斌焦鑫
侯文生+张美玲+史晟+郜娟+高立斌+焦鑫



摘要:将废旧棉纤维和对苯二甲酸(TPA)在水热条件下以一定质量比进行碳化处理,采用X射线衍射分析(XRD)、傅立叶红外光谱分析(FT-IR)、扫描电镜(SEM)、X光电子射线能谱分析(XPS)及元素分析等方法研究TPA对废旧棉纤维物化结构特性的影响。结果表明:水热条件下棉纤维碳化产物形貌为具有无定形碳结构的不规则颗粒或棒状,且表面含有丰富的含氧官能团。随着TPA含量的增加,棒状产物增多,而TPA仅有少量发生降解或接枝到棉纤维碳产物的表面,其余可回收再利用。研究表明,水热条件下TPA虽未直接参与棉纤维的碳化过程,但TPA的存在使得碳化产物形貌多呈带有沟槽的棒状形态,与纯棉纤维碳化产物相比,粒径增大且C/O质量比降低。
关键词:废旧棉纤维;对苯二甲酸;水解;碳化;水热条件
中图分类号:TQ340.41;TQ127.1 文献标志码:A
Influence of Terephthalic Acid on the Hydrothermal Carbonization of Waste Cotton Fiber
Abstract: Carbonized materials were prepared by hydrothermal treatment of waste cotton fiber with terephthalic acid (TPA). The morphology, physical and chemical structural characteristics of the hydrothermally carbonized materials were investigated with scanning X-ray diffraction (XRD), Fouriertransform infrared spectrometer (FTIR), electron microscopy (SEM), X-ray photoelectron spectroscopy(XPS) and elemental analysis. It shows that the hydrothermally carbonized waste cotton fiber is made up of irregular particles or rod-like substances which have amorphous carbon structure and contain rich oxygen functional groups on the surface. The rod-like substances increase along with the increasing of TPA content. However, only a small amount of TPA can be degraded or grafted onto the surface of the carbonized products while the rest are recyclable. Results indicated that TPA did not involve in cotton fiber carbonization process directly, but its existence has increased the size and content of rod-like carbon products, and decreased the (C/O) atomic ratios when compared with pure cotton fiber carbonized products.
Key words: waste cotton fiber; terephthalic acid; hydrolysis; carbonization; hydrothermal conditions
實现废旧涤棉混纺织物的高效回收再利用是一项极具意义的课题。在各种可能的转化途径中,水热法具有反应速率高、环境友好等特点,因而近年来成为研究热点。
目前国内外对废旧涤棉类纺织品的回收再利用基本是对纯棉或纯涤纶织物进行回收处理,针对涤棉混纺织物进行高附加值回收再利用的报道较罕见。王淑花在水热温度为275 ℃下反应 8 h且pH值为 4 时,将棉浆纤维碳化为粒径在 3 ~ 8 μm之间且分散性较好的碳微球;涤纶(PET纤维)在中性条件、水热温度为250 ℃下保温 7 h,降解率为92.9%,对苯二甲酸(TPA)产率达86.4%。研究发现,在亚临界水中,PET水解反应和棉纤维碳化反应有共同的水热反应条件区间,说明涤棉混纺织物可在同一反应条件下共同降解。……
