Synergistically improving interface behavior by designing physical twisting structure and "rigid-flexible" interface layer on ultra-high molecular weight polyethylene (UHMWPE) fiber surface

The application limitations of Ultra -high molecular weight polyethylene (UHMWPE) fiber reinforced composites in different fields can be attributed to their surface chemical inertness and weak interfacial adhesion. Herein, we developed a novel method for preparation of a stable biomimetic layer surface treatment, via the combination use of physical twisting structure and "rigid -flexible" interface layer. Unlike the conventional methods under special conditions, in this method, the UHMWPE fibers were converted into twisting structure, and the efficient nanoparticle deposition facilitated on the fiber surface in the presence of reductive dopamine coating. Moreover, the multi -structured synergy promotes the roughness of the T-UHMWPE fiber, which improves the interface bonding strength of the fibers -reinforced composites. The effectiveness of the modified treatment was evaluated by Fourier transform infrared spectroscopy (FT-IR), microscopic confocal laser Raman spectrometer (Raman), Xray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), contact angle and surface free energy. The surface morphology and interfacial properties of the treatment was evaluated using field emission scanning electron microscopes (FE-SEM) and energy dispersive spectrometry (EDS). The experimental results demonstrated that the interfacial shear strength (IFSS) of the modified T-UHMWPE was improved by 218 %, compared with those of the unmodified UHWMPE fibers. This innovative approach, combining physical twisting structure and "rigid -flexible" interface layer, would provide a valuable potential for the preparation of advanced UHMWPE reenforced composites with high interfacial bond strength.