ISSN:
1435-1536
Keywords:
LLDPE
;
stress-strain behavior
;
yield stress
;
comonomer content
;
molar mass
;
DTA
;
morphology
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A commercial 1-octene LLDPE, Dowlex 2045, was cross-fractionated by dynamic direct extraction and subsequent solution crystallization. Two solution fractions of molecular massM η of about 37 000 and 120 000 were selected for second fractionation by crystallization in xylene at temperatures of 80°, 65°, 50° and 21°C. From the cross fractions thin films were pressed at high temperature and then cooled either in air to room temperature or in a quenching bath to −18°C. From these films small rectangular samples were cut and stretched at room temperature. The stress-strain curves, indicating inhomogeneous drawing, show two characteristic points, A and B, of local curvature maximum. The corresponding yield stresses, σA and σB, were evaluated, and their dependence on structural parameters as molar mass and comonomer content, as well as on cooling rate, affecting the morphology, is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00657982
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