Structural relaxation of PbO–WO3–P2O5 glasses

• Published in: Journal of thermal analysis and calorimetry 2013-12, Vol.114 (3), p.947-954
• Main Authors: Chromčíková, Mária, Liška, Marek, Lissová, Magdaléna, Mošner, Petr, Koudelka, Ladislav
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Applied sciences; Building materials. Ceramics. Glasses; Chemical industry and chemicals; Chemistry; Chemistry and Materials Science; Exact sciences and technology; Glasses; Inorganic Chemistry; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Structure, analysis, properties
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-013-3082-7

The structural relaxation of three compositional series of PbO–WO 3 –P 2 O 5 glasses with composition (0.5 −  x /2)PbO· x WO 3 ·(0.5 −  x /2)P 2 O 5 , x  = 0, 0.1, 0.2, 0.3, 0.4, and 0.5; 0.5PbO· x WO 3 ·(0.5 −  x )P 2 O 5 , x  = 0, 0.1, 0.2, and 0.3; and (0.5 −  x )PbO· x WO 3 ·0.5P 2 O 5 , x  = 0, 0.1, 0.2, 0.3, 0.4, and 0.5 was studied by thermomechanical analysis. The structural relaxation was studied in the transformation region using the Tool–Narayanaswamy–Moynihan’s and Tool–Narayanaswamy–Mazurin’s models. The relaxation function of Kohlrausch Williams and Watts was used. The parameters of both models were calculated by nonlinear regression analysis of thermodilatometric curves measured by thermomechanical analyzer under the constant load. Both models very well describe the experimental data. It was found that the modulus is increasing with increasing amount of WO 3 in all glasses. On the contrary, the width of the spectrum of relaxation times is decreasing with increasing amount of WO 3 in all studied glasses. Both models possess the values of metastable melt thermal expansion coefficient equal to their experimental value.