ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The structure change in spherulites for hydrostatically extruded polypropylene (PP) was studied by the use of internal friction measurements and thermophotometry tests. The onset temperature of the β-loss peak of the PP sample decreases with increasing reduction in area, R. For the extrudates below R=50%, the peak temperature of α-loss shifts to lower temperature. The α and β absorptions for the extrudates up to R=50% become broad and overlap with each other. The intensity of the β-loss peak, Δmax, is maximum for the extrudate with R=50%. The results of tan δ, damping, and the intensity of the β-loss peak indicate that the mechanism of molecular chain deformation is divided into two stages, below and above R=50%. The results are due to spherulitic changes, i.e. the shape of spherulites changed from spherical to elliptical in the extrudates above R=50% and the spherulite with R=50% changed from coarse structure to a finer one by the imposition of hydrostatic pressure.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00352796
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