Identification of natural leather and artificial leather products using FT-IR spectroscopy

Abstract

The development in the artificial leather technology results in products which have properties and features very similar to natural leather. Therefore, scientific method can be used to identify between natural leather and synthetic leather in order to raise consumer confidence. In this research, both cowhide and crocodile leather have been characterized using Burn test, Sodium hydroxide test, surface analysis by Profile Projector and Optical microscope and structure analysis by FT-IR spectroscopic technique. The results showed that natural leather samples released a smell of burning protein from burn test and also part of them can be dissolved in NaOH whereas synthetic leather remains undissolved. In addition, the surface of artificial leather could be finished to natural looking which consists of pores all over the leather surface. However, FTIR analysis of natural leathers was based on five regions of interest, which were 3300-3250 cm^-1, 2960-2920 cm^-1, 1700-1600 cm^-1, 1560-1540 cm^-1 and 1240-1230 cm^-1. These regions related to the vital functional groups on the leathers such as amide group from protein. However, synthetic leather's spectrum pattern is clearly different from natural leather. The study showed that the FTIR technique could be easily used to distinguish between the nature-made and human-made leathers as it is rapid and non-destructive technique.