Characteristics of cylindritic crystallization of polypropylene were studied by means of optical microscopy. It has been shown that a distinct structural memory effect is observed during the cylindritic crystallization. This memory effect can be attributed to thermal stability of row nuclei giving rise to the cylindritic crystallization. Negative or mixed type cylindrites are formed depending on the crystallization temperature (Tc > 410 and Tc < 410 K, respectively). Cylindrites obtained by stepwise crystallization are constructed of segments with different optical characteristics and melting points. Boundary lines of parabolic, hyperbolic, ellipsoidal or linear shape can be developed between the cylindrites and spherulites formed parallel. Equations describing the boundary lines are given in the present publication.
ASJC Scopus subject areas
- Materials Science(all)