Morphology, Phase Composition, and Molecular Mobility in Polyamide Films in Relation to Oxygen Permeability

Autor:	Jean-Marc Lefebvre, O. Persyn, V. Miri, Victor M. Litvinov
Rok vydání:	2010
Předmět:	Morphology (linguistics) Materials science Polymers and Plastics Organic Chemistry Relaxation (NMR) Amorphous solid Inorganic Chemistry Crystallinity Magnetization Oxygen permeability Chemical engineering Polyamide Polymer chemistry Materials Chemistry Proton NMR
Zdroj:	Macromolecules. 43:7668-7679
ISSN:	1520-5835 0024-9297
DOI:	10.1021/ma1014403
Popis:	The effect of phase composition and molecular mobility on oxygen permeability is studied for stretched films prepared from polyamide 6 (PA6) and a blend of PA6 with semiaromatic amorphous polyamide (aPA)−PA6/aPa, which is a random co-polyamide containing iso- and terephthalic chain units. The effect of stretching degree of films on crystallinity and strain-induced immobilization of the amorphous phase is studied by DSC and solid-state proton NMR transverse (T2) magnetization relaxation, respectively. Changes of these parameters upon strain are determined. Crystallinity and Tg are hardly affected by strain, as shown by DSC. Molecular mobility in the amorphous phase of stretched films is largely restricted upon increasing strain. At temperatures well above Tg, the amorphous phase consists of two fractions of nanometer thickness: one behaves like glassy polyamides, and the other one, a semirigid fraction, reveals largely hindered chain mobility. The amount of the glassy-like fraction increases proportionally...
Databáze:	OpenAIRE
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