Chemical/Physical Retting of Flax Using Detergent and Oxalic Acid at High pH

Abstract

An oxalic acid-based system for chemically retting flax is tested and compared with enzymatic retting. The retting effect is substantially higher at pH 10 and 11 than at lower pH levels, and the optimal oxalic acid concentration is 50 mmol. The presence of the strong detergent sodium dodecyl sulfate (SDS) further enhances retting. The rate of retting with the oxalic acid/SDS mixture at pH 10 is strongly temperature dependent, and at 75°C the process is completed within 2 hours. Tests of fiber properties ( e.g., tex, tenacity, and elongation) indicate that the chemical/physical retting method pro duces fibers of textile quality that can be spun into flax-rich blends with cotton.