Fig. 2. Scheme of the rate of polymer formation with temperature for the copolymerisation of butene polysulfone. As the depropagation becomes more significant at higher temperature, the polymer formation rate falls to zero. The ceiling temperature is independent of the initiation mechanism and active species for a chain polymerization conducted at the same initial monomer concentration with low (dark blue) and high (rose) anionic initiator concentration, radical initiator (green), and light of low (orange) and high intensity (light blue). Adapted from ref. 66 with permission from the Royal Society of Chemistry, copyright 1953.