Wen Hongmei, Wang Yulu, Zhu Hongxia, Jin Liqiang, Zhang Feifei
Faculty of Light Industry, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Materials (Basel). 2022 Feb 2;15(3):1167. doi: 10.3390/ma15031167.
Fatliquoring is one of the most important processes in leather making, in which the collagen fibers are split effectively, while the crust acquires a good softness and mechanical strength. The effectiveness of fatliquoring depends not only on the variety and dosage of fatliquoring agent but also on its distribution in hierarchical collagen fiber layers. Up to now, the research about the mass transfer of fatliquoring agent in leather is very limited because quantifying the distribution of invisible fatliquor in leather is very difficult. In this paper, a fluorescent tracing technique based on modified castor oil was established and send used to investigate the mass transfer of fatliquor in leather. The crucial fluorescent tracer was synthesized favorably by the reaction of castor oil, successively with maleic anhydride and 5-aminofluorescein, which was confirmed by FTIR, H NMR and DSC. The fluorescent tracer was pH-sensitive and emitted an intense fluorescent signal at pH 8-10. Then, it was applied to monitor the fatliquoring process in real-time. Compared with Sudan IV or Nile Blue sulphate dyeing tests, this fluorescent tracing technique could conveniently visualize and quantify the penetration and distribution of fatliquor in leather process.
加脂是皮革制造中最重要的工序之一，在此过程中胶原纤维能被有效分散，同时坯革能获得良好的柔软度和机械强度。加脂效果不仅取决于加脂剂的种类和用量，还取决于其在胶原纤维分层中的分布。到目前为止，关于加脂剂在皮革中传质的研究非常有限，因为量化皮革中不可见加脂剂的分布非常困难。本文建立了一种基于改性蓖麻油的荧光示踪技术，并用于研究加脂剂在皮革中的传质。通过蓖麻油先后与马来酸酐和5-氨基荧光素反应成功合成了关键荧光示踪剂，经傅里叶变换红外光谱（FTIR）、核磁共振氢谱（H NMR）和差示扫描量热法（DSC）证实。该荧光示踪剂对pH敏感，在pH 8-10时发出强烈的荧光信号。然后，将其应用于实时监测加脂过程。与苏丹IV或硫酸尼罗蓝染色试验相比，这种荧光示踪技术可以方便地可视化和量化加脂剂在皮革加工过程中的渗透和分布。
