Article
Blends of amorphous-crystalline block copolymers with amorphous homopolymers. Morphological studies by electron microscopy and small angle scattering
Polymer
(1996)
Abstract
A morphological study was performed with symmetric diblock ethylene-propylene copolymer (DEP) and
the binary blends made from DEP and atactic polypropylene (APP) by use of small angle X-ray, light
and neutron scattering, and also scanning and transmission electron microscopy. DEP contains
a crystallizable polyethylene block and an amorphous atactic polypropylene block. Quenching the blends
in liquid nitrogen preserved the morphology in the melt state. This quenching technique revealed that DEP
forms a lamellar microdomain structure and blending DEP and APP includes morphological changes in the
microdomain structures as well as macrophase separation. When the APP chain was shorter than the APP
block, the addition of APP changed the morphology from a lamellar to a bicontinuous cylindrical and then a
discrete cylindrical and finally to a spherical structure. On the other hand, when the APP chain was longer
than the APP block, macrophase separation was observed and only a transition from a lamella to
a bicontinuous cylinder occurred. These morphological transitions in the melt state can be correlated
to differences in the crystallization kinetics of the blends.
Keywords
- blends,
- symmetric diblock copolymers,
- semicrystalline block
Disciplines
Publication Date
1996
Citation Information
William MacKnight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, et al.. "Blends of amorphous-crystalline block copolymers with amorphous homopolymers. Morphological studies by electron microscopy and small angle scattering" Polymer Vol. 37 Iss. 20 (1996) p. 4443 - 4453 Available at: http://works.bepress.com/william_macknight/259/