Open AccessCrystalline plasticity in isotactic polypropylene below and above the glass transition temperature
Author(s) -
Gerald Polt,
Florian Spieckermann,
Harald Wilhelm,
Ch.H. Fischer,
Erhard Schafler,
Sigrid Bernstorff,
M. Zehetbauer
Publication year - 2015
Publication title -
express polymer letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.695
H-Index - 72
ISSN - 1788-618X
DOI - 10.3144/expresspolymlett.2015.81
Subject(s) - tacticity , materials science , glass transition , plasticity , composite material , polypropylene , polymer science , polymer , polymerization
In-situ X-ray diffraction was applied to isotactic polypropylene with a high volume fraction of α-phase (α-iPP) while it has been compressed at temperatures below and above its glass transition temperature Tg. The diffraction patterns were evaluated by the Multi-reflection X-ray Profile Analysis (MXPA) method, revealing microstructural parameters such as the density of dislocations and the size of coherently scattering domains (CSD-size). A significant difference in the development of the dislocation density was found compared to compression at temperatures above Tg, pointing at a different plastic deformation mechanism at these temperatures. Based on the individual evolutions of the dislocation density and CSD-size observed as a function of compressive strain, suggestions for the deformation mechanisms occurring below and above Tg are made