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Deformation and aging of quenched polypropylene
Author(s) -
Gezovich D. M.,
Geil P. H.
Publication year - 1968
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760080306
Subject(s) - materials science , lamellar structure , spherulite (polymer physics) , polypropylene , deformation (meteorology) , diffraction , yield (engineering) , composite material , stress (linguistics) , internal stress , crystallography , optics , polymer , linguistics , philosophy , physics , chemistry
The physical properties, i. e., yield stress and stress‐strain curve of the quenched (“smectic”) form of polypropylene have been shown to be time dependent at room temperature. The yield stress increases linearly with the logarithm of film age. No changes in the x‐ray diffraction pattern, infra‐red spectrum, electron diffraction pattern or morphology have been observed corresponding to this change in physical properties. A molecular mechanism is proposed which will explain this again process. Spherulites of the quenched form have been found to deform affinely when drawn. In contrast to this, slow cooled films show complete destruction of internal spherulite (lamellar) order, indicating a complex mechanism of deformation.