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A simple model of flow‐induced crystallization memory
Author(s) -
Ziabicki Andrzej,
Alfonso Giovanni Carlo
Publication year - 2002
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/1521-3900(200208)185:1<211::aid-masy211>3.0.co;2-b
Subject(s) - crystallization , materials science , nucleation , polymer , crystallization of polymers , flow (mathematics) , thermodynamics , orientation (vector space) , crystal growth , stress (linguistics) , chemical physics , crystallography , chemical engineering , composite material , mechanics , chemistry , physics , mathematics , linguistics , geometry , engineering , philosophy
Flow induced crystallization of polymer systems exhibits strong memory effects. Crystalline structures gradually change when the flow is switched off and the polymer is relaxed prior to crystallization. A simple model based on the multidimensional theory of crystal nucleation [1] is proposed. Steady, potential flow applied to a polymer fluid above melting temperature (T p > T m ) results in molecular orientation of crystallizing units. The flow controls formation of molecular clusters which convert into athermal nuclei when the system is cooled down to crystallization temperature, T c < T m . Orientation effects gradually disappear when the melt is relaxed above T m in the absence of flow or stress.