P[CF3(CF2)5CH2MA-co-MMA] and P[CF3(CF2)5CH2MA-co-BA] copolymers: Reactivity ratios and surface properties

This study aimed at reducing the surface energy of coatings by copolymerization of commonly used monomers with fluorine-containing monomers. Copolymers of 1,1-dihydroperfluoroheptyl methacrylate (FHMA) and methyl methacrylate (MMA) or butyl acrylate (BA) are prepared by low-conversion polymerization in solution. Using 1H-NMR data and nonlinear least-squares data fitting, reactivity ratios of these systems at 80°C are determined to be rFHMA = 1.31, rMMA = 0.76, and rFHMA = 3.15, rBA = 0.38, respectively. We assume that the penultimate unit effect plays an important role in these systems. Introduction of the perfluoroalkyl side chain lowers the polymer surface energy significantly; copolymers of MMA and FHMA show a reduction in total surface energy of about 50 % at a content of 15 mol % FHMA as compared with pure PMMA. The attainable reduction in surface energy is much larger than with, for example, Teflon. This is due to the preferential adsorption of the —CF3 groups of the fluoroalkyl side chain, if compared to that of the —CF2— groups of Teflon. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 159–165, 2001