Polymerization resulting from ultrasonic cavitation

Polymerization due to ultrasonically induced cavitation is reported for a number of compounds: bromobenzene, styrene, isoprene, and methyl methacrylate. The molecular weight of the polymethylmethacrylate produced through ultrasound is considerably lower than that due to normal aging. The bromobenzene and styrene products are dark friable solids. The isoprene product has an ultra-violet absorption suggesting a conjugated system of about ten carbon-carbon bonds in length.