Progress in Organic Coatings 66 (2009) 99–106 Contents lists available at ScienceDirect Progress in Organic Coatings journal homepage: www.elsevier.com/locate/porgcoat Styrenation of triglyceride oil by nitroxide mediated radical polymerization Neslihan Alemdar a , A. Tuncer Erciyes a,∗ , Yusuf Yagci b,∗ a Istanbul Technical University, Department of Chemical Engineering, 34469 Maslak, Istanbul, Turkey b Istanbul Technical University, Department of Chemistry, 34469 Maslak, Istanbul, Turkey article info Article history: Received 13 January 2009 Received in revised form 9 April 2009 Accepted 15 June 2009 Keywords: Styrenated oil Controlled/living polymerization NMRP abstract Styrenated oil was obtained by nitroxide mediated radical polymerization (NMRP) method in the pres- ence of 2,2 ′ ,6,6 ′ -tetramethylpiperidinyl-1-oxy (TEMPO). For this purpose, firstly, macroinitiator having thermally unstable azo groups was obtained with reaction of partial glycerides (PGs) mixture and 4,4 ′ - azobis-4-cyanopentanoyl chloride (ACPC). Then, the macroinitiator was subjected to polymerization with styrene in the presence of TEMPO in order to obtain a copolymer with controlled structure and low poly- dispersity. The products thus obtained were characterized by GPC, 1 H NMR and FT-IR measurements. A classical styrenated oil was also prepared for comparison. The film properties of the products were determined according to the related standards and compared with each other. The product obtained at the end of the 72h in the presence of TEMPO showed to some extent brittle film properties. To improve the film properties, this product was further reacted with the oil-based vinyl macromonomer (MM). The styrenated oil samples prepared by the controlled polymerization method, exhibited relatively low polydispersity (<1.5) and showed good film properties. © 2009 Elsevier B.V. All rights reserved. 1. Introduction Over the past decade, nitroxide mediated radical polymeriza- tion (NMRP) [1–4], together with the other equally important controlled/living radical polymerization (CLRP) techniques such as reversible addition–fragmentation chain transfer polymeriza- tion (RAFT) [5–8] and atom transfer radical polymerization (ATRP) [9–12] have generated a great deal of attention because of its ver- satility in producing complex macromolecular architectures with pre-estimated molecular weights and very narrow polydispersity (M w /M n ). Moreover, CLRP methods do not require strict purifica- tion of monomers and solvents and tolerate a variety of functional groups. For these reasons, they have more advantages than the anionic polymerization technique [13]. ∗ Corresponding authors. E-mail addresses: erciyes@itu.edu.tr (A.T. Erciyes), yusuf@itu.edu.tr (Y. Yagci). NMRP method is conducted in two steps. First, the reactions are carried out at temperatures where initiation is rapid and all of the chains are formed in about at the same time. In the second step, the initiated polymer chains are reversibly capped by a stable free radi- cal such as 2,2 ′ ,6,6 ′ -tetramethylpiperidinyl-1-oxy (TEMPO), to give a dormant living polymer. So, it provides control over the polymer- ization system owing to this equilibrium. This equilibrium is given by Eq. (1) [14]. (1) NMRP has advantages over ATRP and RAFT as the resulting poly- mer is not contaminated with metal ions and avoids the use of malodorous sulfur compounds, respectively [15]. Triglyceride oils are widely used in the production of organic coating materials. In order to obtain better film properties in coating applications, oils are modified with various methods. Among these methods copolymerization of oils with vinyl monomers occupies an important place, styrene being the most widely used monomer [16–23]. In the classical styrenation process, homopolystyrene for- mation is likely to occur and the presence of homopolymer leads to poor film properties. By taking this fact into account, the meth- ods by which homopolymerization can be minimized and polymer 0300-9440/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.porgcoat.2009.06.006