Extraction of a novel tanning agent from indigenous plant bark and its application in leather processing  

作　　者：Raju Kumar Das Al Mizan Fatema Tuj Zohra Sobur Ahmed Khondoker Shahin Ahmed Hemayet Hossain 

机构地区：[1]Institute of Leather Engineering and Technology(ILET),University of Dhaka,44-50,Hazaribagh,Dhaka 1209,Bangladesh [2]Department of Leather Engineering,Khulna University of Engineering&Technology(KUET),Khulna 9203,Bangladesh [3]Department of Leather Engineering,Faculty of Engineering,Ege University,35100 Bornova,Izmir,Turkey [4]BCSIR Laboratories,Chemical Research Division,Bangladesh Council of Scientific and Industrial Research(BCSIR),Dhanmondi,Dhaka 1205,Bangladesh

出　　处：《Journal of Leather Science and Engineering》2022年第1期253-267,共15页皮革科学与工程（英文）

基　　金：the Ministry of Science and Technology,Bangladesh by the National Science and Technology(NST)fellowship(Group:Physical Science,Reg.No:317).

摘　　要：The use of vegetable tanning materials in leather processing has drawn attention as an alternative to basic chromium sulphate for its natural abundance and environmental aspects. In this work, an attempt has been made to extract veg-etable tannins from Xylocarpus granatum bark using different solvents (e.g., water, methanol, ethanol, and chloroform) and compare with conventional vegetable tanning agents such as mimosa and quebracho. The highest extraction efficiency was observed 31.22% by methanol. The presence of tannin content and polyphenolic compounds, e.g. (-)epicatechin (503 mg/100 g dry extract), catechin hydrate (218 mg/100 g dry extract), catechol (29 mg/100 g dry extract) were ensured by UV-Vis, FT-IR spectroscopy and HPLC. Again, condensed tannins, moisture content, and pH of the methanol extracted tannin were found 47.80%, 5.82%, and 3.97 respectively. The leather tanned by Xylocar-pus granatum tannin showed a shrinkage temperature of 86.34 ± 1.52 °C. Other properties such as tensile strength, tear strength, grain cracking load, and distention at grain cracking were comparable to conventional vegetable- tanned leather. The cross-sectional morphology of the tanned leathers was also characterized by scanning electron microscopy (SEM) which revealed a compact structure of the leather fibers. In light of the findings from the study, X. granatum bark tannin could be a well alternative to chromium and a new source of vegetable tannin for the leather industry.

关 键 词：Vegetable tanning agent Strength properties Shrinkage temperature Chrome-free leather Alternative tannin Xylocarpus granatum 

分 类 号：TS529.2[轻工技术与工程—皮革化学与工程]