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Dynamic‐mechanical behavior of highly drawn isotactic polypropylene

1992; Wiley; Volume: 46; Issue: 10 Linguagem: Inglês

10.1002/app.1992.070461011

1097-4628

F. De Candia, G. Romano, А. О. Баранов, É. V. Prut,

Mechanical Behavior of Composites

Abstract Fibers of isotactic polypropylene were obtained by high‐temperature drawing, adopting a two‐stage process. Very high drawing degrees were achieved, more than 40. The physical behavior was analyzed by determining the dynamic‐mechanical relaxation spectra in monoaxial stretching. The results obtained show that the elastic modulus reaches a saturation value at deformation degrees of about 20, well below the drawability upper limit, indicating that above 20 any further drawing does not affect the structure. Moreover the α transition appears weak or absent in the drawn samples, while the β transition is still readily detectable. Both effects agree with Peterlin's model of drawing and with the fiber structure. © 1992 John Wiley & Sons, Inc.