Effect of hydrogen-peroxide treatment on the physico-mechanical properties of flax fibers

Abstract

Flax fibers contain cellulose and different impurities (hemicelluloses, lignin, pectin, waxes and fats, mineral salts, natural coloring matter and water soluble compounds). From the ecological and industrial aspect, hydrogen peroxide is the most acceptable component for modification of flax fibers. The aim of the modification of flax fibers is to remove non-cellulose components and improve the fiber quality without significant changing of the mechanical properties. Flax fibers were treated with hydrogen peroxide solutions at concentrations 1%, 2% and 4% at 50 °C, 80 °C and boiling temperature for time period of 60 min. With the removal of non-cellulosic substances from fibers, it has been achieved a high degree of fiber separation and a significant increase of modified fibers fineness. The value for fineness of modified fibers was reduced about 2-4-fold and the modified flax fibers were softer to the hand, unlike unmodified fibers that are very coarse and stiff. However, the weight loss and removal of lignin, which gives the fibers strength, as well as a partial damage of the cellulose itself during the severity of treatment, brought to reduction in the tensile strength of the modified fibers.