In situ ESR response to temperature evolution of styrene/dibenzoyl peroxide/Di‐TEMPO biradical system

The initial stage of the di‐TEMPO (N,N′‐bis(4‐(2,2,6,6‐tetramethylpiperidin‐1‐yloxyl))diaminobutane) controlled radical polymerization of styrene was investigated by electron spin resonance (ESR) method in a temperature range of 300–410 K. Processes corresponding to three subsequent temperature subranges 300–360, 360–375, and 375–410 K have been discussed. The decrease of concentration of the di‐TEMPO biradicals is faster than for the TEMPO monoradicals in the range 370–390 K. The reduced mobility of capping groups is postulated to be responsible for the differences between TEMPO monoradical and di‐TEMPO biradical mediators. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010