D. Benoit et al., Accurate structural control and block formation in the living polymerization of 1,3-dienes by nitroxide-mediated procedures, MACROMOLEC, 33(2), 2000, pp. 363-370
The living free radical polymerization of 1,3-dienes, such as isoprene and
1,3-butadiene, has been shown to be a facile process in the presence of alk
oxyamine initiators based on a 2,2,5-trimethyl, 4-phenyl-3-azathexane-3-oxy
, 2, skeleton. These alpha-hydride nitroxide derivatives were able to contr
ol the homopolymerization to high conversion and molecular weights from 100
0 to 100 000 amu with polydispersities of 1.06-1.15 readily obtained. Block
and random copolymers based on combinations of 1,3-dienes with a variety o
f functionalized vinyl monomers, such as styrene, acrylate, or methacrylate
derivatives, could also be prepared with similar control. In comparison wi
th 2,2,6,6-tetramethylpiperidinoxy (TEMPO), these new systems represent a d
ramatic improvement in the ability to control the polymerization of 1,3-die
nes and further demonstrate the versatility of nitroxide-mediated living fr
ee radical procedures.