真皮革与人工革的快捷鉴别

Identification of Natural Leather and Artificial Leather( PU or PVC)

分别取真皮革样品20种,人工革样品30种,通过显微镜法、燃烧法、烟气法、溶剂法、红外光谱法和热重分析法进行鉴别。真皮革断裂截面处明显看见粒面层和网状层,且拉出的纤维束长短、粗细不一,而人工革除布基纤维外,断裂截面处无纤维抽出。用10%氢氧化钠溶液处理,真皮革溶解成细小颗粒,人工革形态变化不大;真皮革燃烧时发出烧焦的羽毛气味,人工革发出刺激性的气味;真皮革烟气溶于水后pH值在7.5左右,而人工革的pH值在5.0以下,PVC革的pH比PU革低;人工革在某些溶剂中完全或接近溶解,真皮革无法用溶剂溶解。最终,采用红外光谱法和热重分析法作为进一步鉴别的依据。

20 kinds of natural leather samples and 30 kinds of artificial leather samples were identified by methods of microscope, burning, flue gas, organic solvent, infrared spectroscopy and thermogravimetry respectively. The results show that the fracture section of natural leathers can clearly see grain surface layer and reticular layer, and the length and diameter of the fiber bundles are different. Artificial leathers are found only base cloth fibers on the fracture section. Treating with 10% sodium hydroxide solution,＇ natural leathers are dissolved into tiny particles and artificial leathers change a little. Natural leathers release burned feather smell when burn and artificial leathers release irritant smell. The pH is 7.5 after the flue gas of natural leathers dissolves into water and the pH of artificial leathers is below 5.0, and the pH of PVC is lower than that of PU. Artificial leathers can entirely or close to dissolve in some organic solvents and natural leathers is insoluble in these solvents. Finally, the infrared spectroscopy and thermogravimetry are used for further identification.