Branched poly(butyl acrylate) was obtained from pulsed‐laser polymerizations carried out in bulk and in solution between ?16 and 60 °C. The predominantly short branches are formed by backbiting. The Arrhenius temperature dependence of the backbiting rate is calculated, and the activation energy of this process was found to be remarkably higher than that of propagation. Branching thus increases with temperature leading to broader SEC traces and difficulties in the accurate determination of kp.
Arrhenius plot of kfp2 versus 1/T determined experimentally.