Investigation of Surface-Liquid Interaction Relationships in Attapulgite Loaded Wet-Spun Polyurethane Composite Fibers Using Multivariate Analysis.

Attapulgite (ATP)-loaded wet-spun polyurethane (PU) fibers were produced to investigate the effect of ATP on the surface structure and liquid interaction behavior of PU fibers under static immersion. ATP incorporation changed the surface morphology of PU fibers from smooth and compact to rougher and more porous structures, as confirmed by SEM-EDS and BET analyses. ATP incorporation increased BET surface area from 2.236 to 17.144 m2/g and the total pore volume from 0.0050 to 0.0755 cm3/g. These structural changes promoted water uptake and methylene blue interaction by improving wetting-assisted liquid penetration and dye diffusion through accessible mesoporous pathways. ATP incorporation also improved the thermal and mechanical behavior of the fibers at appropriate loading levels. The onset degradation temperature increased from 252.35 °C for neat PU to 270.53 °C with 3 wt.% ATP loading. The highest tensile strength value of 10.026 MPa was achieved at 1 wt.% ATP loading. Pearson correlation and principal component analyses showed that methylene blue interaction was more closely associated with pore diameter and pore volume than with ATP content alone. The results also indicate that ATP incorporation is an effective strategy for tailoring the pore accessibility, liquid interaction, and structure-dependent performance of wet-spun PU composite fibers.