The application and mechanism study of microwave irradiation in traditional industries have attracted considerable attention owing to the unique thermal and athermal effects that could lead to unexpected benefits in high-efficiency and clean production. Herein, we report the investigation of the aluminum tanning under microwave irradiation upon using hide powder and skin pieces, respectively, as simulants of real hide or skin. The aluminum tanning process and the tanned products under microwave heating (MWH) were studied and compared with those of conventional water bath heating (WBH) as the controls. For the tanning system of hide powder, the tanning effluents were analyzed in terms of pH, conductivity, dielectric constant and aluminum content, and the tanned powder was investigated by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and FT-IR spectroscopy. For the skin piece system, the pH and aluminum content of tanning effluents were also determined, and at the same time, DSC, TG, SEM, FT-IR and shrinkage temperature were used to illustrate the actions of microwaves on the structure and properties of the tanned pieces. The results show that aluminum reactivity in the penetration and binding process of collagen fibers in hide powder and skin pieces improved using microwave treatment. The residual aluminum content was greatly reduced by microwave heating action, and the increased amount of aluminum with evener distribution was observed in the tanned products. Microwave irradiation also resulted in the tanned products with better thermal stability and thermal decomposition resistance. This work further promotes application of microwave treatments for aluminum-based tanning in leather industry.

中文翻译：

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微波辐射下生皮粉和皮块的铝鞣制

微波辐射在传统工业中的应用和机理研究由于其独特的热和非热效应而备受关注，这些效应可能导致高效清洁生产中的意想不到的好处。在此，我们报告了在分别使用生皮粉和生皮片作为真实生皮或生皮的模拟物的微波辐射下对铝鞣制的研究。研究了微波加热（MWH）下的铝鞣制过程和鞣制产品，并与常规水浴加热（WBH）进行了比较。对于皮革粉的鞣制系统，分析了鞣革废水的pH，电导率，介电常数和铝含量，并通过差示扫描量热法（DSC）研究了鞣制粉末，热重分析（TG）和FT-IR光谱。对于皮件系统，还确定了鞣革废水的pH和铝含量，同时，使用DSC，TG，SEM，FT-IR和收缩温度来说明微波对微波辐射的结构和性能的作用。晒黑的碎片。结果表明，微波处理可以改善胶原蛋白纤维在生皮粉和皮肤碎片中的渗透和结合过程中的铝反应性。通过微波加热作用，残余铝含量大大降低，并且在鞣制产品中观察到铝含量增加且分布更均匀。微波辐射还使鞣制产品具有更好的热稳定性和抗热分解性。