Oriented Overgrowths of Poly(l-Lactide) on Oriented Isotactic Polypropylene: A Sequence of Soft and Hard Epitaxies.
Macromol Rapid Commun
; 39(20): e1800353, 2018 Oct.
Article
en En
| MEDLINE
| ID: mdl-30027645
The crystallization behavior of an amorphous poly(l-lactide) (PLLA) layer deposited on uniaxially oriented isotactic polypropylene (iPP) substrate is been studied by atomic force microscopy (AFM) and electron microscopy combined with electron diffraction. A patterned PLLA structure with two fixed lamella and chain orientations is observed. Electron diffraction demonstrates that the major lamellar set is oriented with molecular chains perpendicular to the chain direction of the iPP. The minor lamellar set is inclined at ≈64° to both the iPP chain axis direction and the lamellae of the major set as judged from both the bright field electron micrograph and the AFM image. The orientation of the main set is explained in terms of "soft" epitaxy or graphoepitaxy, in which PLLA chains oriented parallel to the ditches of the iPP substrate caused by alternatively arranged crystalline and amorphous regions. The minor set is due to a homoepitaxy of PLLA with parallelism of the helical paths. The orientation of this minor set of lamellae therefore depends on and can help determine the chirality-l or d-of the PLA investigated.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Poliésteres
/
Polímeros
/
Polipropilenos
/
Cristalización
Idioma:
En
Revista:
Macromol Rapid Commun
Año:
2018
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Alemania