Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2002
Publication Date: 3/1/2002
Citation: LIU, C. ABSORPTION OF GLYCEROL AND ITS EFFECTS ON THE PHYSICAL PROPERTY OF A COLLAGENOUS MATERIAL - LEATHER. JOURNAL OF APPLIED POLYMER SCIENCE. 2003. V. 87. P. 1221-1231. Interpretive Summary: Leather is commonly treated with lubricants called fatliquors to impart softness and flexibility. Traditional lubricants, however, are known to impair the mechanical strength of leather. They also do not promote the retention of essential moisture, thus leaving the leather prone to over-drying. We have investigated the use of glycerol as a lubricant for leather. Glycerol is a humectant with the ability to retain moisture, thereby preventing the leather from over-drying due to environmental changes, such as low humidity and high temperature. This investigation has demonstrated that leather treated with glycerol is significantly reduced in its stiffness, indicating the lubrication function of glycerol in leather. This research suggests that humectants are potential alternatives or additives to traditional fatliquors to help prevent aged leather products from becoming brittle and fragile.
Technical Abstract: An aqueous solution of glycerol was applied to leather to evaluate its effects on the physical properties of leather, particularly stiffness. Young's modulus, initial strain energy and acoustic emission methods were used to characterize the stiffness of resultant leather treated with these glycerol solutions. Measurements revealed that glycerol treatment significantly reduced the stiffness of the dried leather, indicating the strong lubrication function of glycerol to leather. Experiments were also conducted to investigate the mechanism of glycerol adsorption into the leather matrix. Fick's second law of diffusion was employed to system- atically derive a mathematical model for absorption rate. The effect of temperature on the absorption rate was also included in the model by incorporating the Arrhenius equation into Fick's second law of diffusion. The resultant model fits the experimental data very well. It not only depicts the mechanism of absorption, but also predicts the absorption rate as a function of key variables.