Ba. Howell et al., SYNTHESIS AND PROPERTIES OF 2,2,6,6-TETRAMETHYL-1(1-PHENETHYLOXY)PIPERIDINE, AN INITIATOR FOR LIVING FREE-RADICAL STYRENE POLYMERIZATION, Polymer bulletin, 37(4), 1996, pp. 451-456
An initiator for living free radical polymerization may be prepared by
trapping the benzylic ethylbenzene radical with the stable 2,2,6,6-te
tramethylpiperidinyl-1-oxy (TEMPO) radical. The adduct, 2,2,6,6-tetram
ethyl-1-(1-phenethyloxy)piperidine (TMPEP), smoothly undergoes thermal
fragmentation at temperatures approaching 140 degrees C to afford an
active carbon radical capable of initiating polymerization and a passi
ve mediating nitroxyl radical to reversibly cap and preserve the propa
gating polymer chain.