The radical homo-and co-polymerization of 2

2

6

6-tetramethyl piperidinyl methacrylate (TM-PM) with various initiators have been studied. It was found that

with azo-type initiators

the poly-merization proceeded readily

while with acyl peroxide initiators

the polymerization was inhibitedeffectively because of the formation of the stable TMPM-oxyl radical

identified by ESR. Thisobservation was further confirmed by the absence of inhibition effect on the addition of 2

2

6

6-tetramethyl 4-piperidinol to the polymerization system

whereas remarkable inhibition was observed on the addition of the stable 2

2

6

6-tetramethyl 4-piperidinol N-oxyl radical.The reaction mechanism was discussed.We also found that when TMPM reacted with BPO in petroleum ether

N-benzoyloxy 2

2

6

6-tetramethyl 4-piperidinyl methacrylate was formed

and this novel compound has been characterized with IR

ESR

NMR and Mass Spectroscopy.