Evaluation of the termination mode in the radical polymerization of 2,2,2-trifluoroethyl α-fluoroacrylate

The mode of termination of 2,2,2-trifluoroethyl alpha-fluoroacrylate (FATRIFE) in radical polymerization was studied, and only termination by recombination occurred, which led to telechelic macromolecular structures. The radical polymerization in acetonitrile was carried out to synthesize oligomers with a low number average degree of polymerization ((DPn) over bar)(cum) (about 20), using tert-butylcyclohexyl peroxydicarbonate (TBCPC) as initiator at 75degreesC. The initial [TBCPC](0)/[FATRIFE](0) molar ratio was monitored to evaluate its influence on the ((DPn) over bar)(cum) of alpha-fluoroacrylic oligomers. The H-1 NMR analysis of the polymers showed that the ((DPn) over bar)(cum) values obtained were higher than 40, in spite of a high C-0 value. To explain these results, the mode of termination was evaluated using the 10.27 following kinetic law: R-pi approximate to [I-2](0)(0.27) [M](0)(1.24). The development of kinetic relationships allowed us to 0 calculate the ratio k(prt) /k(i)(.)k(p) as about 17-30 mols l(-1), and to confirm that primary radical termination (PRT) was in competition with bimolecular macromolecular termination (BMT). (C) 2002 Society of Chemical Industry.