Summary: Well‐defined poly(N‐vinylcarbazole) [poly(NVC)] was synthesized by macromolecular design via interchange of the xanthates (MADIX)/reversible addition‐fragmentation chain transfer (RAFT) polymerization. The homopolymers with controlled molecular weights ($\overline M _{\rm n}$ = 3 000–48 000) and low polydispersities indices ($\overline M _{\rm w} /\overline M _{\rm n}$ = 1.15–1.20) were obtained by the polymerization of NVC with AIBN in the presence of O‐ethyl‐S‐(1‐phenylethyl) dithiocarbonate as a xanthate‐type chain transfer agent (CTA). Good control of the polymerization was confirmed by the linear first‐order kinetic plot, the molecular weight controlled by the monomer/CTA molar ratio, linear increase in the molecular weight with the conversion, and the ability to extend the chains by the second addition of the monomer.Radical polymerization of NVC in the presence of CTA and plot of number‐average molecular weight (circles) and polydispersity (squares) as a function of conversion.magnified imageRadical polymerization of NVC in the presence of CTA and plot of number‐average molecular weight (circles) and polydispersity (squares) as a function of conversion.

Four-arm poly(N-vinylcarbazole), poly(NVC), stars were synthesized by reversible additionfragmentation chain transfer (RAFT) polymerization/macromolecular design via interchange of xanthates (MADIX) using three different xanthate-type tetrafunctional chain transfer agents (CTAs). Two Z-designed CTAs having different R (leaving) groups, in which the Z (stabilizing) groups are linked to the core, and one R-designed CTA were compared. The R-group approach was found to be the most efficient for the controlled synthesis of fourarm poly(NVC) stars having a low polydispersity and controlled molecular weights. Amphiphilic star block copolymers were synthesized by the polymerization of NVC using the poly(acrylic acid) star, which was prepared from the R-designed tetrafunctional CTA. The characteristic assembled structures and optical properties of the amphiphilic star block copolymers in selective solvents were investigated by dynamic light scattering (DLS), UV-vis, and fluorescence spectroscopic methods.

Poly(N-vinylcarbazole) [poly(NVC)] stars were synthesized by macromolecular design via interchange of xanthate (MADIX)/reversible addition-fragmentation chain transfer (RAFT) polymerization. Four-armed poly(NVC) stars with controlled molecular weights and low polydispersities were obtained using a tetrafunctional xanthate, in which the stabilizing groups are linked to the core. The controlled character of the polymerization was also confirmed by the linear increase in the molecular weight with the conversion. The comparison of the polymerization behaviors using the tetrafunctional xanthate and a monofunctional one suggested that the multifunctional core has a clear effect on the polymerization kinetics, but has no significant influence on the controlled character of the polymerization.

Cover: The graphic shows the use of the xanthate-type chain transfer agent for controlled radical polymerization of N-vinylcarbazole. Good control of the polymerization was confirmed by the narrow polydispersity of the products, feasibility to control molecular weight based on the monomer to chain transfer agent ratio (left figure), linear increase in molecular weight with the conversion (middle figure), and ability to extend the chains by the second addition of the monomer (right figure).