Effect of ultrasonic frequency on polymerization of styrene under sonication
Effect of ultrasonic frequency on polymerization of styrene under sonication
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DOI：
10.1016/s1350-4177(00)00064-x
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发表时间：
2001-04-01
影响因子：
8.4
通讯作者：
Nomura, H
中科院分区：
文献类型：
--
作者：
Kojima, Y;Koda, S;Nomura, H
研究了超声波频率23.4、45.7、92、518kHz和1MHz下50℃超声处理下苯乙烯聚合的影响。在超声处理下进行聚合，其超声强度与卟啉分解的反应速率相同。聚合速率的大小按 92、45.7 和 23.4 kHz 的顺序增加。在 518 kHz 和 1 MHz 的高频下，没有观察到聚合。这些事实意味着有效聚合的最佳频率在 92 至 518 kHz 范围内。对于92、45.7和23.4 kHz的照射频率，超声处理3小时时的平均数分子量分别为5.5 x 10(4)、8.0 x 10(4)和11.5 x 10(4)。与在 23.4 和 45.7 kHz 下获得的结果相比，在 92 kHz 下超声处理 3 小时可得到具有非常高的多分散性（约 5.0）的聚苯乙烯。这些观察结果表明超声处理下的聚合受到照射频率的影响。 (C) 2001 Elsevier Science B.V. 保留航空权利。
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.