Carbon disulfide sonopolymer: A comparison with other carbon disulfide polymers

Intense ultrasonic treatment caused CS₂ sonolysis with formation of several products like sulfur, carbon subsulfide C₃S₂, and a black insoluble sonopolymer. The sonolysis products was analyzed by electronic spectroscopy and liquid chromatography (HPLC). The black insoluble sonopolymer was studied in detail by FT-IR spectroscopy and was found to be chemically similar to the CS₂ photopolymer and to the piezopolymer. FT-IR shows that the sonopolymer prepared at room temperature is the ladder carbon subsulfide polymer (C₃S₂)_x, having the linear polymer -[S-(C=S)-S-(C=S)-]_x-, as minor component. When sonication is conducted at −78°C, FT-IR spectrum shows that the sonopolymer in addition to carbon subsulfide polymer (C₃S₂)_x contains the carbon disulfide dimer (C₂S₄) previously detected in the piezopolymer.

A discussion of the mechanism of sonolysis of carbon disulfide shows that the “hot spot” theory involving high pressure and temperature generated by cavitational bubbles can explain the results at −78°C, but not at room temperature. To explain sonolysis at 0°C or higher temperature, electric breakdown inside cavitational bubbles should be considered.