Polylactic acid fiber structure and absorption properties of disperse dyes

Comprehensive thermal analysis and X-ray diffraction were used to analyze the thermal stability and microstructure of the staple and filament of polylactic acid fibers.The results showed that these two types of fiber have the same crystalline structure and stability,but the staple has higher crystallinity and melting point than the filament.The paper further measured the adsorption isotherm of C.I.disperse red 145 and C.I.disperse orange 61 on the two types of fiber,respectively.It was found that the adsorption followed the Nernst model.The filament exhibits a stronger ability to adsorb disperse dyes,particularly for C.I.disperse orange 64,its partition coefficient and saturation value were higher than those of the staple by one time.It can be concluded that the difference in adsorption caused by the microstructure varied with the type of disperse dye.In the case of same crystalline pattern of fiber molecules,the crystal size and crystal perfection have impacts on adsorption of disperse dyes besides the main factor of the crystallinity in fiber molecules.