On the kinetics of polymer crystallization under shear

✍ Scribed by H. Janeschitz-Kriegl; G. Krobath; W. Roth; A. Schausberger

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 613 KB
• Volume: 19
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(83)90044-7

✦ Synopsis

A novel measuring technique for the crystallized layer growth is described, in which the influence of shear flow on the lateral heat conduction is avoided at least to a first approximation (uncoupling of momentum and energy equations). Under the circumstances created by this technique, an unravelling of two stages of layer growth is successfully predicted (growth into the undercooled melt at low contact times, limitation of growth by the speed of cooling at high contact times). The actual layer growth is measured for the melt of an industrial isotactic polypropylene with the aid of an on-line mechanical measurement and confirmed by microscopic measurements on microtom cuts taken from the completely solidified film, as released from the shearing unit. Various aspects of morphology, crystal modification and growth are discussed. Possible trends for future investigations are indicated.