Rheology of tin fluorophosphate glass/polyamide 12 hybrids in the low concentration regime

• Published in: Journal of rheology (New York : 1978) 2007-11, Vol.51 (6), p.1171-1187
• Main Authors: Urman, Kevin, Schweizer, Thomas, Otaigbe, Joshua U.
• Format: Article
• Language: English
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Physics; Properties and characterization; Rheology; Rheology and viscoelasticity
• ISSN: 0148-6055; 1520-8516
• DOI: 10.1122/1.2789954

Phosphate glass (Pglass)/polymer hybrids are a unique material class that promises to help fulfill the growing need for new advanced materials. Rheological investigations into Pglass/polyamide 12 hybrids have shown a strong dependence on temperature and composition. Strong negative deviations from the log-additivity rule are also observed for these materials as well as a reduction in the activation energy for viscous flow. Hybrids containing < 2 vol. % Pglass are rheologically simple fluids that display temperature independence in plots of storage modulus versus loss modulus. Hybrids containing ≥ 2 vol. % Pglass are rheologically complex and do not obey the time-temperature superposition principle. Through application of Han plots, we identified a structural change that occurs in hybrids containing ≥ 2 vol. % Pglass at temperatures in excess of 220 ° C . This microstructural change induces an apparent yield stress in the material at these elevated temperatures. It is believed that the microstructural change is due to enhanced interactions that occur at elevated temperatures between the compatible pure components of the hybrids.