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Crystalline Amorphous Interfaces in Polymer Crystals

A. Peterlin ; Camme Dreyfus Laboratory, Research Triangle Institute, Research Triangle Park North Carolina, 27709, U.S. A.

Puni tekst: engleski, pdf (18 MB) str. 335-349 preuzimanja: 90* citiraj
APA 6th Edition
Peterlin, A. (1970). Crystalline Amorphous Interfaces in Polymer Crystals. Croatica Chemica Acta, 42 (2), 335-349. Preuzeto s https://hrcak.srce.hr/197557
MLA 8th Edition
Peterlin, A.. "Crystalline Amorphous Interfaces in Polymer Crystals." Croatica Chemica Acta, vol. 42, br. 2, 1970, str. 335-349. https://hrcak.srce.hr/197557. Citirano 07.03.2021.
Chicago 17th Edition
Peterlin, A.. "Crystalline Amorphous Interfaces in Polymer Crystals." Croatica Chemica Acta 42, br. 2 (1970): 335-349. https://hrcak.srce.hr/197557
Harvard
Peterlin, A. (1970). 'Crystalline Amorphous Interfaces in Polymer Crystals', Croatica Chemica Acta, 42(2), str. 335-349. Preuzeto s: https://hrcak.srce.hr/197557 (Datum pristupa: 07.03.2021.)
Vancouver
Peterlin A. Crystalline Amorphous Interfaces in Polymer Crystals. Croatica Chemica Acta [Internet]. 1970 [pristupljeno 07.03.2021.];42(2):335-349. Dostupno na: https://hrcak.srce.hr/197557
IEEE
A. Peterlin, "Crystalline Amorphous Interfaces in Polymer Crystals", Croatica Chemica Acta, vol.42, br. 2, str. 335-349, 1970. [Online]. Dostupno na: https://hrcak.srce.hr/197557. [Citirano: 07.03.2021.]

Sažetak
Crystalline polymer solids are never ideally crystallized. From
the density defect one may formally derive a finite crystalline
and amorphous component. The study of polyethylene single crystals
by different methods suggests a spatial separation of the
components: a crystalline core and two quasi amorphous surface
layers containing the chain folds. At the interface the amorphous
loops are fixed in the crystal lattice. The space requirement of
the amorphous conformations can be only met by the assumption
of varying loop length . . This immediately increases the entropy
content of the loops and partly compensates for the reduction
caused by the loop ends fixed at the interface and by the limitation
of space accessible to the loops by the existence of the
crystal lattice. The high energy requirement of the shortest loops
with an excess of gauche conformations favors large loops and
hence increases the thickness of the surface layer. The values
obtained for strictly adjacent reentry of all loops are still below
the experimental data. A perfect fit seems possible if one assumes
that there are a few loops with nonadjacent reentry and some chains
with one end free. The former are a consequence of crystallization
kinetics and the latter result from the finite number of extremely
long loops surpassing the length of single molecules but also from
the chain ends of all molecules of the sample because there is a
clear tendency of their concentration on the surface of the crystal.

Hrčak ID: 197557

URI
https://hrcak.srce.hr/197557

Posjeta: 147 *