Pressure dependence of sound velocity, equation of state, and structure of vitons

Viton A500 and carbon-filled composite Viton are important materials as binders for high explosives and as seals over a wide temperature range. These applications require a thorough understanding of the elastic, thermodynamic, and structural properties over a broad pressure range. Using a Paris-Edinburgh press, the sound velocity measurements were measured by ultrasonic pulse-echo method and x-ray radiography up to a pressure of 7 GPa. Pressure effects on the short and medium range order in the amorphous component and the residual a crystalline component were determined using in-situ x-ray diffraction. The results were compared with measurements on pure polyvinylidene fluoride (PVDF), Sylgard, and polychlorotrifluoroethylene (Kel-F). SEM compositional analysis of Viton A500, its carbon-filled composite, and pure PVDF sample was performed to determine sample homogeneity and the origin of measured residual crystallinity.