The relationship between Zeta-Potential and pull-out shear strength on modified UHMWPE fiber reinforced epoxy composites

UHMWPE fiber exhibits high performance, featuring high tensile strength and modulus, because of its extended chain structure. However, this fiber demonstrates some defects, such as low melting point, creep, and poor interfacial bonding with resin. Therefore, it is still not widely applied in composites. This research attempted to improve the performance by applying interfacial treatment to the fiber, using polypyrrole (PPy) synthesized through oxidation. The interfacial shear strength was evaluated using the results of a pull-out test and a Zeta Potential. The UHMWPE fiber was exposed to Pgr treatment at various temperatures. The PPy-modified fiber was then impregnated with epoxy to generate the composites. The effects of the modification were also examined. The performance of the composites was determined by the Zeta Potentials of the fiber and resin, using an EKA electrokinetic analyzer. The interfacial shear strength was determined by the pull-out test. The morphology of fiber was observed by SEM. Results show that the shear strength of the interface between the PPy-treated UHMWPE fiber and epoxy increased 215%. The correlation between the Zeta Potential and the interfacial shear strength was also observed.