Stereospecific radical polymerization of fluoroalkyl acrylates

The free-radical polymerization of 2,2,2-trifluoroethyl acrylate (TFEA), 1,1,1,3,3,3-hexafluoro-2-propyl acrylate (HFiPA) and perfluoro-tert-butyl acrylate (PFtBA) was carried out under various conditions and the stereostructure of the obtained polymers was investigated. Most polymerizations of the three monomers afforded polymers rich in diad syndiotacticity (r) in bulk or in solution; the r-specificity was higher in the HFiPA and PFtBA polymerization than in the TFEA polymerization. Although the tacticity was nearly independent of reaction temperature during the polymerization of TFEA, the r-specificity increased by lowering the reaction temperature during the polymerization of the other two monomers. The polymerization stereochemistry was also affected by the reaction solvents including toluene, tetrahydrofuran, and fluoroalcohols. It was noted that the stereochemistry of the polymerization of HFiPA and PFtBA also depended on the monomer concentration, and a lower monomer concentration led to a higher r-specificity. By optimizing the aforementioned reaction conditions, the poly(HFiPA) having r = 81% (polymerization in tetrahydrofuran at −98 °C at [M]o = 0.2M) and the poly(PFtBA) having r = 77% (polymerization in toluene at −78 °C at [M]o = 0.2M) were obtained. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1024–1032, 2000