Obtaining the ratio of termination rate constants of poly (methyl methacrylate) by the ultrasonic scission method

Abstract

The termination step in radical polymerization occurs either by combination or by disproportionation. The termination mechanism of poly (methyl methacrylate) in sonochemical environment is studied by the ultrasonic scission method. The method is improved to give quantitative results by incorporating non-linear least squares analysis of the data. The Chi square map obtained by fitting the data to Schmid's equation gives the ratio of the rate constants for termination by disproportionation and by combination as k<inf>td</inf>/k <inf>tc</inf>. = 2.6 ±0.4. © 2006 Elsevier B.V., All rights reserved.