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Study of the molecular orientation heterogeneity in polypropylene injection‐molded parts by Raman spectroscopy
Author(s) -
Martin J.,
Margueron S.,
Fontana M.,
Cochez M.,
Bourson P.
Publication year - 2010
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.21524
Subject(s) - materials science , raman spectroscopy , polypropylene , raman microscope , tacticity , optical microscope , microscopy , mold , confocal , microscope , composite material , confocal laser scanning microscopy , raman microspectroscopy , polarized light microscopy , polarization (electrochemistry) , optics , raman scattering , scanning electron microscope , polymer , biomedical engineering , chemistry , medicine , physics , polymerization
Polarized Raman microspectroscopy has been used to study oriented‐skin layers induced in injection‐molded isotactic polypropylene (iPP) parts. A method based on the intensity sensitivity of several Raman bands to laser light polarization was employed to estimate the degree of molecular orientation in iPP. The skin‐core molecular orientation heterogeneity in injection‐molded iPP is then evaluated via two different experimental methods. Results show that an in‐depth profile using micro‐Raman confocal technique is as valuable as an edge profile performed on a sample cross‐section because both are correlated with optical microscopy measurements. Both Raman measurements are in good agreement with optical microscopy measurements. The skin development was found to be narrowly related to the shear strain rate at the mold walls. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers