The free radical polymerization of methylacrylate has been investigated at 80+/-1 degrees C for 60 min in 1,4-dioxan using p-bromophenacyl dimethyl sulphonium ylide as initiator and degradative chain transfer agent up to 23% conversion. No gelation occurred due to auto acceleration leading energy and the value of k(p)(2)/k(t) were calculated as 72 kJ mol(-1) and 18x10(-2) Ls(-1), respectively. The radical mode of polymerization was confirmed by ESR and the effect of hydroquinone. A possible mechanism of the system is also proposed.