Mercapto-modified polypropylene fibers were prepared by a process involving an extrusion followed by spinning of mixtures of PP and EVA modified with mercapto groups (EVASH). The analysis of the surface of these fibers by X-ray photoelectronic spectroscopy (XPS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), surface tension and scanning electronic microscopy indicated that the polar component (EVASH) is located closed to the fiber surface. The epoxy composites containing these modified fibers displayed a considerable increase of the impact resistance. This result can be attributed to the good interfacial adhesion between matrix and PP fiber and the ductile characteristic of the fiber. The dynamic-mechanical behavior also suggests the interfacial adhesion.
Polypropylene fiber; mercapto groups; surface analysis; EVA copolymers; epoxy resin; composite
