Deformation behaviors in isotactic polypropylene during rolling

Wide angle X-ray diffraction is used to measure the texture evolution of isotactic polypropylene (iPP) during rolling. Pole figures, orientation distribution functions and crystallinities of the rolled iPP are obtained and calculated. The texture evolution is also simulated by the modeling. It can be drawn that the main deformation mechanisms occurred at low strain is the coarse slips on few planes and the amorphization because of the special mother and daughter lamellae of the material, which leads to the crystallinity decreases greatly. As the true strain increases, mother and daughter lamellae are broken, then, the following deformation does not be controlled by the special structure of alpha-iPP. The basic deformation mechanisms in the rolled iPP is the crystallographic slips, and the main slip systems are (010)[001] and (100)[001] chain slips and (010)[100] transverse slip and so on. Amorphization is also a deformation mechanism which may take place as an alternative to crystallographic slip depending on the crystallographic orientation of a lamella. The [001]aEuro-RD fiber texture, which includes several (hk0)[001] texture components is the main texture component in the rolled iPP.