Relationship between microstructure and properties of false-twist textured and stabilized polylactide. Part 2: physicochemical characterization, accessibility of the amorphous phase and dyeing behavior

Polylactide fibers (PLA), textured by false twist at different temperatures (135, 150 and 165º C) and draw ratios (1.30, 1.35 and 1.40) were stabilized by the application of a continuous thermal treatment at 100º C and 50 m/min. The effect of thermal stabilization on the microstructure was determined by physicochemical tests such as iodine sorption or differential solubility. Iodine sorption and differential solubility are closely related to the crystallinity of the samples. Stabilization enhances crystallinity and orientation with the result that differences between the samples are diminished. Color value differences, albeit reduced, in some cases exceed the accepted limits. Color absorption is mainly dependent on the orientation and accessibility of the amorphous phas