Atom transfer radical polymerizations of (meth)acrylic monomers and isoprene

Atom transfer radical polymerizations (ATRP) of methyl methacrylate (MMA), ethyl acrylate (EA), and isoprene through the use of CuBr/N,N,N′,N′,N″-pentamethyl diethylenetriamine catalyst and ethyl bromoproprionate initiator were studied as a function of polymerization parameters. Chemical structure, percentage yield and molecular weight of products were analyzed by gravimetry, FTIR, ¹H-NMR and GPC techniques. Polymerized products having a considerable high percentage yield was obtained from the polymerization of MMA and EA. The percentage yield and molecular weight of PMMA increased with reaction temperature, reaction time, monomer concentration and initiator content. There was also an optimum catalyst content corresponding to the maximum yield and molecular weight of PMMA. The polymerization of EA also showed a similar trend. ATRP of isoprene, however, resulted in only a trace amount of product, irrespective of reaction parameters. The low product yield from the ATRP of isoprene was attributed to a poor solubility of CuBr and tris[2-(dimethylamino)ethyl]amine catalyst in isoprene and the limited reaction temperature.