Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2011
Publication Date: 7/1/2011
Citation: Liu, C., Latona, N.P., Ramos, M. 2011. Effects of alpha-tocopherol addition to polymeric coatings on the UV and heat resistance of a fibrous collagen material--chrome-free leather. Journal of Applied Polymer Science. Available: http://onlinelibrary.wiley.com/doi/10.1002/app.34129/fullDOI. Interpretive Summary: Ultraviolet light (UV) and heat can have a detrimental effect on the color and mechanical properties of leather. This research aims to develop a process treatment that is environmentally friendly and yet significantly increases the UV and heat resistance of leather. We added alpha-tocopherol (Vitamin E), a natural antioxidant, to the coatings of leather that had been tanned with an organic tannage without using chromium salts. Following exposure to artificial sunlight, the treated samples were evaluated for color stability and mechanical properties for the efficacy of UV- and heat resistance. Observation showed that leather treated with alpha-tocopherol resulted in significant improvement in strength retention and color fading resistance against UV radiation and heat. This research will expand the demand for domestic production of high quality, durable leather, thereby contributing to the viability of the domestic tanning industry.
Technical Abstract: UV and heat resistance are very important qualities of leather because most leather products are constantly exposed to outdoor environments. In recent years, we have focused on using environmentally friendly antioxidants that will improve the UV and heat resistance of chrome-free leather. Tocopherols are well-known antioxidants commonly used in the cosmetic and food industries. They are known as potent free radical scavengers and highly protective agents for collagen fibers against UV damage. We have investigated their potential to be applied to the leather coating for improving UV resistance. Experiments were conducted by adding 5 to 12% alpha-tocopherol to the polymeric coatings that acting as finishes to the grain of chrome-free leather. The treated samples were tested in a weatherometer, where they were exposed to artificial sunlight. Colorfastness and mechanical property tests showed that alpha-tocopherol significantly improved UV and heat resistance of leather. Dynamic mechanical tests showed that alpha-tocopherol reduced the harden effects on leather caused by UV irradiation.