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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 5: New Instruments and Methods

CPP 5.4: Talk

Monday, March 22, 2010, 11:00–11:15, H39

Hyperspectral CARS imaging of polyolefine deformation — •Gregor Hehl¹, Gulnara Yu. Nikolaeva², Stefan Gomes da Costa¹, and Andreas Volkmer¹ — ¹3rd Institute of Physics, University of Stuttgart — ²RAS, Moscow, Russia

We report on the hyperspectral coherent anti-Stokes Raman scattering (CARS) imaging of the initial stages of polyolefine deformation. Many polyolefines undergo uniaxial stretching with formation of a so-called necking region where the axes of most of the macromolecules become oriented along the direction of deformation [1]. To investigate the structural changes of macromolecular orientation without perturbing the polymer structure of interest, labelfree hyperspectral CARS imaging [2] of polyethylene and isotactic polypropylene was performed. Spectral CARS hypercubes providing both spectral and spatial information of the polymers for each image voxel have been collected with 5-cm-1 and sub-micron resolution, respectively. Based on the corresponding phase-retrieved Raman hypercube using the Maximum Entropy method [3] and on the characteristic Raman bands of the polymers, hyperspectral data processing results in pseudo-color images of the degrees of molecular orientation and of crystallinity. Unlike conventional X-ray measurements, IR and Raman microspectroscopies, we demonstrate unprecedented fast 3D chemical mapping of local physical structure information of polymers with high spatial resolution and at high spectrum acquisition rate. [1] S. A. Gordeev et al., Polymer Science, Ser. A 38 (1996), 517, [2] A. Volkmer, J. Phys. D: Appl. Phys. 38 (2005), R59, [3] E. Vartiainen et al., Appl. Spectrosc. 50 (1996), 1283.