Study on catechol/tetraethylenepentamine and nano zinc oxide co-modifying ultrahigh molecular weight polyethylene fiber surface to improve interfacial adhesion

To improve interfacial adhesion to rubber matrix, a lower cost surface modification strategy of ultrahigh molecular weight polyethylene (UHMWPE) fiber was proposed by replacing expensive dopamine with the two-component system of catechol/tetraethylenepentamine (CAT/TEPA) and then depositing nano zinc oxide (ZnO NPs). By Michael addition reaction or Schiff base reaction between CAT and TEPA, the CAT/TEPA layer was coated on the fiber surface, and further served as a secondary functional platform to realize ZnO NPs deposition through coordination. The surface morphology, chemical structure and composition, wettability and thermal property of the UHMWPE fibers were investigated to evaluate the process and effect of the surface modification. The results of the single-filament tensile test indicated that the tensile strength of the UHMWPE fibers has no deterioration after the modification treatment. In comparison with the original fiber, the pull-out test showed that the highest interface adhesion between the modified UHMWPE fibers and rubber matrix increased by 80.4%. Additionally, it was found that the appropriate zinc ion concentration played an important role in the modification effect.