ISSN:
0098-1273
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
A semicrystalline polymer having a large repeat unit, as does nylon-11, is particularly suitable for seeking correlation between the orientation of the lattice and the basal planes of the lamellar crystals. In filter mats of nylon-11 single crystals, the basal planes of the lamellae are parallel to (00l) crystallographic planes; the chain axis is tilted with respect to the mat plane. By planar extrusion, bulk double oriented specimens with a nearly single texture can be prepared: the basal planes of the lamellae are parallel to (00l) planes and the chain axis is along the extrusion direction. Doubly oriented samples of nylon-11 having a double texture have been obtained by unidirectional rolling. In these samples, the chain axes are along the rolling direction; the basal planes of the lamellar crystals are not parallel to (00l) planes. It has been proposed that lamellae consist of blocks of six hydrogen-bonded planes shifted by one monomer unit. The parallelism between basal planes of lamellae and (00l) planes is obtained again in rolled samples annealled in contact with formic acid. Those annealed samples are similar to filter mats with respect to the orientation of the lamellar basal planes but they remain doubly oriented at the level of the unit cell; they have a long spacing larger than filter mats of single crystals.
Zusätzliches Material:
10 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1984.180220803
