Six new poly(amide-imide)s (PAIs) 8a-f were synthesized from the direct polycondensation reaction of 1,1-bis[4-(trimellitimido)phenoxy]methane 6 with various aromatic diamine 7a–f. The polymerization reactions produced a series of thermally stable and organosoluble PAIs with high yield and good inherent viscosity. The resulted polymers were fully characterized by means of FTIR and ¹H-NMR spectroscopy, elemental analyses, inherent viscosity, and solubility tests. Also thermal properties of the PAIs 8a–f were investigated using thermal gravimetric analysis (TGA) and derivative of thermaogravimetric (DTG) analysis. dicarboxylic acid 6 was synthesized from the reaction of 1,1-bis[4-aminophenoxy]methane 4 with trimellitic anhydride 5 in a solution of glacial acetic acid/pyridine (Py) at refluxing temperature.

Acoustic cavitation is the formation and collapse of bubbles in liquid irradiated by intense ultrasound. The speed of the bubble collapse sometimes reaches the sound velocity in the liquid. Accordingly, the bubble collapse becomes a quasi-adiabatic process. The temperature and pressure inside a bubble increase to thousands of Kelvin and thousands of bars, respectively. As a result, water vapor and oxygen, if present, are dissociated inside a bubble and oxidants such as OH, O, and H₂O₂ are produced, which is called sonochemical reactions. The pulsation of active bubbles is intrinsically nonlinear. In the present review, fundamentals of acoustic cavitation, sonochemistry, and acoustic fields in sonochemical reactors have been discussed.

New thietane-containing 1,2,4-triazole derivatives were synthesized, and their structure was determined by ¹³C and ¹H NMR spectroscopy and mass spectrometry. The electronic absorption spectra of the new compounds in the ultraviolet and visible regions and their photoluminescence and luminescence excitation spectra were analyzed, and photoluminescence quantum yields were estimated.