Degree of crystallinity of linear polyethylene from wide-angle x-ray diffraction

1967 ◽  
Vol 5 (10) ◽  
pp. 925-929 ◽  
Author(s):  
M. R. Gopalan ◽  
L. Mandelkern
2007 ◽  
Vol 130 ◽  
pp. 251-256 ◽  
Author(s):  
Czesław Ślusarczyk ◽  
Kazimiera Suchocka-Gałaś

Wide-angle X-ray diffraction (WAXD) and the scanning electron microscopy (SEM) were used to determine the morphology of crystalline phase of blends of poly(ethylene-oxide) (PEO) and styrene-acrylic acid (S-AA) copolymers neutralized with sodium ions (Na+). In this study, we investigated the effects of blend composition and the content of ionic groups in amorphous ionomers on the degree of crystallinity and the crystallite sizes. It was found that the degree of crystallinity of PEO in the blends decreases both with increasing S-ANa(6.4) content and with increasing ANa content. The sizes of PEO crystallites, measured both in the direction perpendicular and parallel to the polymer axis, are almost independent of ionic groups content in the amorphous component of the blends but they decrease with increasing S-ANa(6.4) content. For the blends containing small amounts of PEO the confined crystallization of this polymer were observed. The final crystalline morphology of these blends, observed by SEM method, is different in comparison to that formed without spatial confinement.


2007 ◽  
Vol 168 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Valerio Causin ◽  
Carla Marega ◽  
Pietro Carresi ◽  
Sergio Schiavone ◽  
Antonio Marigo

Polymer ◽  
2004 ◽  
Vol 45 (18) ◽  
pp. 6341-6348 ◽  
Author(s):  
S. Stoeva ◽  
A. Popov ◽  
R. Rodriguez

Polymer ◽  
2001 ◽  
Vol 42 (21) ◽  
pp. 8965-8973 ◽  
Author(s):  
Zhi-Gang Wang ◽  
Xuehui Wang ◽  
Benjamin S. Hsiao ◽  
Saša Andjelić ◽  
Dennis Jamiolkowski ◽  
...  

Carbon ◽  
2015 ◽  
Vol 87 ◽  
pp. 246-256 ◽  
Author(s):  
Périne Landois ◽  
Mathieu Pinault ◽  
Stéphan Rouzière ◽  
Dominique Porterat ◽  
Cristian Mocuta ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1572
Author(s):  
Baku Nagendra ◽  
Paola Rizzo ◽  
Christophe Daniel ◽  
Lucia Baldino ◽  
Gaetano Guerra

Poly(ʟ-lactide) (PLLA) films, even of high thickness, exhibiting co-crystalline and crystalline α phases with their chain axes preferentially perpendicular to the film plane (c⊥ orientation) have been obtained. This c⊥ orientation, unprecedented for PLLA films, can be achieved by the crystallization of amorphous films as induced by low-temperature sorption of molecules being suitable as guests of PLLA co-crystalline forms, such as N,N-dimethylformamide, cyclopentanone or 1,3-dioxolane. This kind of orientation is shown and quantified by two-dimensional wide-angle X-ray diffraction (2D-WAXD) patterns, as taken with the X-ray beam parallel to the film plane (EDGE patterns), which present all the hk0 arcs centered on the meridian. PLLA α-form films, as obtained by low-temperature guest-induced crystallization, also exhibit high transparency, being not far from those of the starting amorphous films.


Sign in / Sign up

Export Citation Format

Share Document