Conformation of the propagating radical of triphenylmethyl methacrylate as studied by esr

Abstract

An ESR study on the radical polymerization of triphenylmethyl methacrylate was carried out in 2-methyltetrahydrofuran over a temperature range from −90°C to 30°C. A well-resolved 9-line spectrum was observed at−90°C, a 5-line spectrum at −50°C, and a 13-line spectrum at 0°C. When the observation temperature was raised from 0°C to 30°C, a 5-line spectrum was recorded again. This change in the spectrum with temperature was explained on the basis of two stable conformations and the interchange between them through the free rotation of the radical end. The existence of these two conformations was supported by the calculation of conformation energy. © 1981, The Society of Polymer Science, Japan. All rights reserved.