Abstract
In a wide range of drawing temperatures (20 to 150° C) and draw-ratiosλ (5 to 20) the axial long periodL T is a unique function of temperature. It is completely independent of the long period of the starting material which was varied within wide limits (125 to 350 A). The gradual transformation of the long period observed at small draw-ratio (λ between 1 and 5) from the valueL 0 of an undrawn sample to the limiting valueL T>L 0 of highly drawn polypropylene (λ ≥ 5) could be demonstrated on samples withL 0 larger thanL T. The change of long period is abrupt, indicating a discontinuous step in the transformation from the original microspherulitic into the fibre structure. These results may be interpreted in the same manner as in the case of polyethylene. During plastic deformation in the neck the lamellae are broken into small folded chain blocks which are then incorporated into the microfibrils, the basic building element of the fibre structure. The work of deformational forces must so mobilise the chains in the blocks that they get rearranged with a new long period, corresponding to the temperature of drawing.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.