Related Experiment Video
Updated: Jun 17, 2026

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties
Published on: September 1, 2018
The beta-spherulite morphology of isotactic polypropylene investigated by Raman spectroscopy
J Martin1, P Bourson, A Dahoun
1Laboratoire Matériaux Optiques, Photonique et Systèmes, Université Paul Verlaine de Metz et Supélec, UMR CNRS 7132, 2 rue Edouard Belin, 57070 Metz, France.
Abstract:
Raman spectroscopy is used to investigate the alpha- and beta-crystalline polymorphs of isotactic polypropylene. Raman spectra of the polymorphs show some minor differences, in particular the wavenumber shifting of certain scattering bands, which reflect the environment of an isolated macromolecular chain within the packing unit cell of the different crystal forms. For example, the shifting of the 842 cm(-1) scattering band, which is the most susceptible band to cause intermolecular interactions, is used to generate a structural map of one beta-spherulite among alpha-spherulites with a well-defined resolution. Anisotropy of the crystalline phase orientation within a beta-spherulite is also investigated by performing polarized Raman spectroscopy measurements. Differences in the polarized spectra are then finely exploited to map the radial lamellae orientation distribution within one beta-spherulite.
More Related Videos
Related Concept Videos
Polymer Classification: Stereospecificity
Raman Spectroscopy: Overview
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
Molecular Weight of Step-Growth Polymers
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
Polymer Classification: Crystallinity
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Polymer Classification: Architecture
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.

