Abstract

Two different samples of cow softy leather (identified as CSG0 and CSG3) were prepared from a cow wet-blue of Indian origin. CSG0 was the control sample and CSG3 had 3% glutaraldehyde added to the process. Other unit operations (physical and chemical) were the same in both samples. Thermal, mechanical and hydrodynamic swelling behaviour of these samples was studied in order to correlate it with the cross-linking densities of the samples.

The hydrodynamic swelling behavior was studied in three different solvents (viz. water, toluene and xylene), assuming definite solvent-bovine collagen interaction parameters, cross-link densities were evaluated by applying the Flory-Rehner equation.

Regarding the mechanical behaviour, some distinguished theoretical models (e.g. Mooney-Rivlin, Flory, and Martin, Roth & Stiehler (MRS)) were tried for fit with the results obtained in stress-strain analyses. A few constants for Cr-tanned cow leather were derived, the value of constant A in MRS equation remained in the range of 0.9-1.0 and constant B in Flory’s equation remained in the range of 0.001-0.005, not reported previously in the literature. It was found that glutaraldehyde raised crosslinking density of chrome-tanned leather from 2.59 x 10-3 mol.m-3 to 3.27 x 10-3 mol.m-3, which is reflected in CSG3 greater thermal resistance, but the physical degree of cross links, calculated from Flory-Rehner equation, decreases which is reflected in CSG3 poor solvent resistance in comparison to CSG0.