Effect of maleic anhydride grafted polypropylene on structure of polypropylene/polyamide 6 blend fiber

The effect of maleic anhydride grafted polypropylene (hereafter "MAH-PP") on the structure of blend fibers of polypropylene (PP) and polyamide 6 (PA6) was investigated. Although undrawn fibers of pure PP or PA6 do not show crystalline orientation, undrawn blend fibers without MAH-PP show low crystalline orientation. Moreover, in undrawn blend fibers containing MAH-PP, distinct crystalline orientation of PP was observed. In the case of drawn fibers, blend fibers containing MAH-PP in an amount of 10 phr or more showed broader diffraction peaks of PA6 crystals in wide-angle X-ray diffraction than did blend fibers having an MAH-PP content of 5 phr or less or pure PA6 fibers. Small-angle X-my diffraction clearly showed that, in all blend fibers, the long period structure does not depend on MAH-PP content. When the blend fibers were annealed at 180degreesC, which is higher than the melting point of PP, one scattering peak was observed in blend fibers having MAH-PP content of 10 phr or more. In contrast, two scattering peaks were observed in blend fibers having an MAH-PP content of 5 phr or less.