Berlin 2001 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 19: Poster: New Methods, Thin Polymer Films, Monolayers
CPP 19.16: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT1
Surface Rheology of Polymers near the Glass Temperature as Investigated by Light Diffraction from Surface Corrugation Gratings — •Kirstin Petersen, Nanang Suarna, and Diethelm Johannsmann — Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
Using light diffraction we investigated hot-embossed surface gratings. The gratings were imprinted at temperatures above the glass temperature, Tg, and afterwards cooled down to temperatures close to Tg. Competition of surface tension and viscous stress governs the time-dependent decay of the polymer grating. In the case of sinusoidal gratings the complex shear modulus G(ω) can be derived from the decrease in the grating amplitude.
We performed experiments close to Tg with both poly(methyl methacrylate) (PMMA) and PMMA doped with azo dye.
For PMMA of varying molecular weight we produced master curves for the storage and loss shear moduli by means of the temperature time superposition principle and compared them to the bulk data.
The dye doped PMMA showed a faster decay of the grating amplitude when exposed to UV-light.