Regensburg 2004 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 15: POSTER: Polymers and Biomaterials

CPP 15.17: Poster

Tuesday, March 9, 2004, 17:00–19:00, B

EFFECT OF CROSS-LINKING AND REDUCED DIMENSIONS ON THE INTERNAL FRICTION IN POLYMERS — •Tatjana Haramina, Hans-Georg Brion, and Reiner Kirchheim — Institut fuer Materialphysik, Uni-Goettingen, Tammanstr. 1, D-37077 Goettingen

The capacity of materials to damp out vibrations (internal friction) is a function of a time lag between stress and strain and is related to anelastic strain. The anelastic strain of polymer materials results from sliding of chains, movements of segments and side groups. This internal friction can be observed by means of mechanical spectroscopy.

The vibrating reed apparatus is developed to measure the damping of supported amorphous polymer films. The damping is observed at about 520Hz at the temperature range from 300K to 500K. The relaxation processes lead to peaks in mechanical spectra.

Photo-cross-linking of Poly(Vinyl Cinnamate) should decrease mobility of polymer chains and influence the internal friction. The opposite effect is expected from thin polymer films, where because of the big influence of the opened surface the molecular mobility should increase.