Shear-induced crystallization of polypropylenes: effect of molecular weight

The crystallization kinetics of three polypropylenes with different molecular weights was studied during shear under isothermal condition with a fibre pull-out device. Nucleation and growth under shear were observed and compared to static conditions. The crystalline growth rate was measured both in...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials science 1999-05, Vol.34 (9), p.2089-2102
Main Authors: JAY, F, HAUDIN, J. M, MONASSE, B
Format: Article
Language:English
Subjects:
Applied sciences
Beta phase
Crystallization
Density
Engineering Sciences
Exact sciences and technology
Fiber pullout
Materials
Materials science
Morphology
Nucleation
Organic polymers
Physicochemistry of polymers
Polypropylene
Properties and characterization
Shear
Spherulites
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The crystallization kinetics of three polypropylenes with different molecular weights was studied during shear under isothermal condition with a fibre pull-out device. Nucleation and growth under shear were observed and compared to static conditions. The crystalline growth rate was measured both in static condition and under shear. In static condition, the morphologies are α-phase spherulites and are formed from nuclei which are randomly distributed. Under shear α-phase morphologies are still observed but the nucleation density and the growth rate depend on the shear-rate. The nucleation density is strongly enhanced by shear and acts as the main factor on the overall kinetics. The growth rate increases with the shear-rate, but the basic growth mechanisms seem to be unmodified. β phase appears after shear during the relaxation of the orientation.
ISSN:0022-2461
1573-4803
DOI:10.1023/A:1004563827491