Physical modification of polypropylene. III. Novel morphology of polypropylene and poly(ethylene-co-vinyl alcohol) with epoxy blend fibers

In this study, the novel morphology of polypropylene (PP) and poly(ethylene‐co‐vinyl alcohol) (EVOH) blend fibers is described. More precisely, the blend fibers of PP–EVOH containing a small amount of EVOH (1, 3, 5, 7, and 9% by weight), with and without epoxy (1 wt %), have been melt‐spun at a constant spinning velocity (500 m/min). For the as‐spun fiber, both the initial modulus and the tenacity increased with the increase in the EVOH content. The blend fibers with three draw ratios (2, 3, and 4) drawn at room temperature. The scanning electron microscopic study showed that a draw ratio of 2 reveals little about the morphological changes, whereas a draw ratio of 4 showed a streak structure perpendicular to the fiber axis for PP–EVOH (91/9 wt %) blend fibers. In addition, epoxy (1 wt %) containing PP–EVOH (91/9 wt %) blend fiber showed latitudinal streaks. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1049–1057, 1999