Morphology and Viscoelastic Properties of Polystyrene Blended with Fully Condensed Polyhedral Oligomeric Silsesquioxanes
MICHIGAN STATE UNIV EAST LANSING DEPT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCE
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Polyhedral oligomeric silsesquioxane POSS offers a unique approach to examine the effect of molecularly dispersed nanoscopic fillers on rheological properties of entangled polymer melts. Experiments were performed using a nearly-monodisperse molecular weight polystyrene PS blended with varying amounts of two fully condensed POSS molecules surrounded with phenethyl and styrenyl groups. Due to the chemical similarity between these organic moieties surrounding the silicon-oxygen framework SiO1.5 of POSS and PS, we were able to obtain polymer blends with molecular dispersed nanoscopic fillers needed to study the effect of intermolecular nanoparticle-nanoparticle interactions and the associated intramolecular interactions on the dynamics of the polymer chains. Differential Scanning Calorimetry DSC, Wide-angle X-ray Diffraction WAXD and Transmission Electron Microscopy TEM were used to characterize the thermal properties and morphologies of the POSSPS blends. Smallstrain oscillatory shear andor tensile method was used to probe the dynamics of polymer chains as influenced by the addition of different chemical moiety of POSS at the glass transition, rubbery state and the terminal-flow transition regions. Results obtained from the thermal and mechanical characterization methods were compared with morphological observations to better understand the structure-property relationship of polymers containing molecularly dispersed nanoscopic fillers.
- Organic Chemistry
- Polymer Chemistry
- Atomic and Molecular Physics and Spectroscopy