Study on Biodegradability of Wool and PLA Fibers in Natural Soil and Aqueous Medium

Wool, a natural keratin fiber, and polylactic acid (PLA), a so-called biodegradable man-made fiber, were assessed on their biodegradability under natural soil and aqueous medium conditions. Cotton, a natural cellulose fiber, was used as positive control. The biodegradation of the three samples were evaluated at 35°C for 42days by the time-dependent changes in weight loss, strength loss and morphology in both conditions. The experimental results indicate that biodegradation activities in natural soil was more efficient and faster than that in aqueous medium; The order of their degradation rates are: cotton>wool>PLA fiber, that implies the natural fibers are more easily degradable than man-made biodegradable PLA fiber; and the mechanical properties decreased faster than biodegradation rate.