ACCELERATED WEATHERING TESTS ON PROTEIN FIBERS

Abstract

Protein-based textiles, such as wool and silk, possess special properties and they are ranked higher on the hierarchical scale than the cellulosic ones (e.g., cotton, linen, hemp), in terms of quality. Wool is composed of keratin as the main protein component and silk consists of approx. 80% fibroin and 20% sericin. The degradation of protein-based fibers is a complex process and it is influenced by temperature, humidity and light. Also, these factors may favor a perfect environment for the development of certain microorganisms, which leads to further degradation. In the case of wool fibers, the mechanism of biodegradation involves keratinolysis (sulfitolysis, proteolysis and deamination) and for silk this mechanism is based on the proteolytic decomposition of sericin and fibroin. For the present work, protein-based fibers (wool and silk) were subjected to an accelerated aging process by using UV light, temperature and humidity. Samples from both types of fibers have been collected at a fixed time interval. The level of degradation was evaluated in terms of changes in fiber morphology, using Scanning Electron Microscopy. Also, an Energy Dispersive X-Ray spectrum was recorded in order to estimate the composition at different degrees of degradation of the samples. Moreover, chromatic parameters measurements were carried out in order to quantify the color modifications of the fibers.

Keywords

• protein fibers
• wool
• silk
• textiles degradation