Xanthates designed for the preparation of N‐Vinyl pyrrolidone‐based linear and star architectures via RAFT polymerization

Abstract

ABSTRACTNovel xanthate RAFT agents, RAFT1‐5, designed for the preparation of a range of novel N‐vinyl pyrrolidone‐based polymeric materials with linear and star architectures via RAFT polymerization are reported. Ethyl pyrrolidone moiety was included in the structures of the xanthates as a part of R (RAFT1‐3) or Z group (RAFT4) to evaluate their effect on the polymerization and to impart homogeneity in the resulting products. The xanthates were designed to fragment to give primary (RAFT1), secondary (RAFT2 and 4), and tertiary radicals (RAFT 3) allowing evaluation of their effect on polymerization. RAFT5 was designed to produce polymeric materials with four‐arm architectures. RAFT1 showed comparable characteristics as conventional radical polymerization. RAFT2 and RAFT4 exhibited living/controlled polymerizations, owing to the combination of stable secondary radical species and incorporation of ethyl pyrrolidone moiety as the R and Z group, respectively. RAFT2 and RAFT5 gave first examples of random copolymers of NVP and VAc with linear and four‐arm star architectures, all exhibiting monomodal distributions and narrow dispersity. The four‐arm PVAc star was used as a macroCTA to synthesize amphiphilic four‐arm star PVAc‐block‐PNVP. The TEM investigation showed the formation of spherical micelles with an average diameter of about 60 nm. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 775–786