POLYMERIZATION OF N-ETHYLMALEIMIDE WITH CYCLIC KETENE O,N-ACETALS AS CATALYST

Isopropylidene-3,4,4-trimethyl-oxazolidine 3 is an initiator for the r adically and anionically induced polymerization of N-ethplmaleimide (N EMI) (Scheme 2). An electron transfer from the CT-complex of NEMI/3 le ads to the radical anion/radical cation pair. In THF (epsilon = 7.58) diradicals result from these processes. connected with a radical homop olymerization of NEMI (experiment A). The polymerization is inhibited by TEMPO and not by H+-ions (experiments B and G). In NEMI as ''solven t'' (experiment E), which possesses a high dielectric constant, we pos tulate an anionic mechanism for the NEMI homopolymerization. The polym erization also takes place in the presence of TEMPO and it is inhibite d by H+-ions (experiments F,C).