Poly[styrene-co-(N-vinylcarbazole)] copolymers with controlled molecular weights and narrow polydispersities were synthesized by nitroxide-mediated "living" free radical copolymerization using an initiator/capping agent system consisting of benzoyl peroxide (BPO) and the stable nitroxyl radical 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO). The copolymerization behaves in a "living" fashion and allows the synthesis of poly[styrene-co-(N-vinylcarbazole)]/polystyrene block copolymers via a controlled chain-extension reaction of the prepared copolymers with styrene.

Polystyrendpoly[styrene-co-(butyl methacrylate)] block copolymers with controlled molecular weights and with polydispersities generally below mw/mn = 1,45 and partially as low as U,,,/m,, = 1,19 were synthesized by a free radical bulk copolymerization using a 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO)-capped polystyrene macroinitiator. The influence of the macroinitiator concentration on the block copolymerization was studied. The polymerization rates are independent of the macroinitiator concentration and are close to that of thermally self-initiated styrenehutyl methacrylate copolymerizations showing the important role of self-initiation for N-oxyl mediated free radical polymerizations.

Poly(styrene‐co‐N‐vinylcarbazole) copolymers with controlled molecular weights and narrow polydispersities were synthesized by N‐oxyl‐controlled free radical copolymerization using benzoyl peroxide as initiator and 2,2,6,6‐tetramethylpiperidine‐N‐oxyl as terminating agent. To improve the low polymerization rates, the radical initiator dicumyl peroxide (DCP) was introduced and its effects on the polymerization rate, the molecular weight and the polydispersity were studied. It was demonstrated that the introduction of DCP leads to a significant enhancement of the polymerization rate and that copolymers with high N‐vinylcarbazole contents as well as N‐vinylcarbazole homopolymer can be obtained. The enhancement of the polymerization rate corresponds to a decrease in the number of chain breaking reactions which leads to polymers with lower polydispersities compared with those polymerized at the same monomer conversion without DCP. This could be proved via comparative chain‐extension experiments with styrene leading to poly(styrene‐co‐N‐vinylcarbazole)‐block‐poly(styrene) diblock copolymers.

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