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Molecular orientation in drawn smectic and crystalline isotactic polypropylene
Author(s) -
De Candia F.,
Russo R.,
Vittoria V.,
Iannelli P.
Publication year - 1988
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.760281506
Subject(s) - materials science , tacticity , amorphous solid , quenching (fluorescence) , phase (matter) , orientation (vector space) , composite material , crystallography , polypropylene , elastic modulus , modulus , optics , polymer , organic chemistry , fluorescence , geometry , chemistry , physics , mathematics , polymerization
The drawing behavior of two polypropylene films of different structures was analyzed. The two films differ as a consequence of different quenching conditions. At low temperature, a biphasic smectic‐amorphous system was obtained, while quenching at 100°C produced a biphasic crystalline‐amorphous system. The drawing of samples was carried out at 110°C at which temperature the smectic phase is not stable and is transformed into the crystalline α‐form. The initial structure affects the drawing behavior and the properties of the drawn samples. The mechanical, optical, and X‐ray analyses clearly show that high molecular orientation is achieved at lower deformations in the initially smectic sample. In particular, the amorphous phase is highly oriented, inducing higher axial elastic modulus.