New approach for the synthesis of graft copolymers under metal-free conditions: Rop and photo-ATRP

The discovery of controlled/living radical polymerization (CLRP) methods has brought make the difference to synthetic polymer chemistry due to their unique advantages (controllable molecular weight, low molecular weight distribution, polymers with functional groups, homogeneity at micro level, etc.) compared to traditional techniques. These techniques enable the production of polymeric materials that are difficult or impossible to obtain using traditional methods. Among CLRP techniques, atom transfer radical polymerization (ATRP) is the most widely used method. In the traditional ATRP method, high temperatures (90-120 °C) are generally required in addition to low oxidation state copper complex (CuBr, CuCl) catalysts. This situation has prevented extensive use of the method in several respects. To eliminate these problems, new methods called light-induced metal-free ATRP that eliminate the need for metal complexes have been introduced in the recent past. In addition, a similar approach has lead to research on the development of metal-free alternatives to other traditional polymerization methods that involve the use of metals. For example, alternatives to ring-opening polymerization (ROP), which can be traditionally carried out under the influence of heat and in the presence of tin octoate (SnOct2) catalyst, have been investigated and alternatives that do not involve the use of heat/metal catalyst have been developed. Within the scope of the thesis, a new synthetic alternative based on the combination of the mentioned metal-free ATRP and ROP methods to produce graft copolymers, a very important type of polymer, will be developed. The reactions to be carried out sequentially will be carried out under completely metal-free conditions. Thus, a new and completely environmentally friendly route for the rapid preparation of graft copolymers will be introduced to the literature. In this context, firstly, by following the relevant literature, a specially designed functional monomer (chloro functional ε-caprolactone, α-Cl-ε-CL) was obtained via Baeyer-Villiger (BV) oxidation of α-chlorocyclohexanone with m-chloroperbenzoic acid (mCPBA). Then, ROP ε-CL and α-Cl-ε-CL in the presence of DPP catalyst was prepared and PCL containing Cl groups was obtained. Then, this structure was used as a macroinitiator in the polymerization of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) by ATRP to obtain graft copolymers. The obtained graft copolymer was characterized by 1H-NMR, GPC, FT-IR and WCA.