Copolymerization of sodium styrene sulphonate and vinylpyrrolidone under ultrasonic irradiation

The effect of ultrasonic irradiation on copolymerization between sodium styrene sulphonate and vinylpyrrolidone was investigated quantitatively at frequencies of 20, 40, and 540 kHz. Acceleration of the rate of polymerization under sonication was observed at three frequencies. The yields of copolymer depended on the frequency and the maximum ultrasonic effect was observed in the frequency range from 20 to 540 kHz. The rate of copolymerization increased with increasing acoustic intensity at frequencies 20 and 40 kHz. The molecular weight of the produced polymer decreased at the shorter reaction time and thereafter increased with the reaction time. The molecular weight was almost independent of the used frequencies.