Journal
ULTRASONICS SONOCHEMISTRY
Volume 8, Issue 2, Pages 75-79Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S1350-4177(00)00064-X
Keywords
frequency effect; polymerization of styrene; average-number molecular weight; polydispersity
Categories
Ask authors/readers for more resources
The effect of ultrasonic frequency on polymerization of styrene under sonication at 50 degreesC was studied at the frequencies of 23.4, 45.7, 92, 518 kHz and 1 MHz. Polymerization under sonication was carried out at the ultrasonic intensity that gives the same reaction rate of decomposition of porphyrin. The magnitude of the polymerization rate increases in the order of 92, 45.7 and 23.4 kHz. At the high frequencies of 518 kHz and 1 MHz, no polymerization was observed. These facts mean that there is an optimum frequency in the range from 92 to 518 kHz for effective polymerization. The average-number molecular weights at the sonication time of 3 h are 5.5 x 10(4), 8.0 x 10(4) and 11.5 x 10(4) for the irradiated frequencies of 92, 45.7 and 23.4 kHz, respectively. Sonication for 3 h at 92 kHz gives polystyrene with very high polydispersity, about 5.0, in comparison with the results obtained at 23.4 and 45.7 kHz. These observations indicate that polymerization under sonication is influenced by the irradiated frequency. (C) 2001 Elsevier Science B.V. Air rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available