Temperature-induced oligomerization of polycyclic aromatic hydrocarbons at ambient and high pressures.

Temperature-induced oligomerization of polycyclic aromatic hydrocarbons (PAHs) was found at 500-773 K and ambient and high (3.5 GPa) pressures. The most intensive oligomerization at 1 bar and 3.

High-Pressure-High Temperature (HP-HT) Stability of Polytetrafluoroethylene: Raman Spectroscopic Study Up to 10 GPa and 600 ℃.

The increasing demand for use of polymers at extreme conditions makes important the exploration of their behavior in a wide pressure and temperature range, which remains unknown for polytetrafluoroethylene (PTFE), one of the most common materials. An in situ Raman spectroscopic study of PTFE shows that it is stable within the range of 2-6 GPa at 500 ℃ and up to 12 GPa at 400 ℃. At T > 500 ℃ and P > 3.

Thermal equation of state of solid naphthalene to 13 GPa and 773 K: in situ X-ray diffraction study and first principles calculations.

In a wide range of P-T conditions, such fundamental characteristics as compressibility and thermoelastic properties remain unknown for most classes of organic compounds. Here we attempt to clarify this issue by the example of naphthalene as a model representative of polycyclic aromatic hydrocarbons (PAHs). The elastic behavior of solid naphthalene was studied by in situ synchrotron powder X-ray diffraction up to 13 GPa and 773 K and first principles computations to 20 GPa and 773 K.