Surface Properties of the Random Copolymer of Polyfluoroalkyl 2-(polyfluoroalkyl)acrylate with Methyl Meth a crylate Effect of Two Long Polyfluoroalkyl Chains

Abstract

A novel fluoromonomer with two long polyfluoroalkyl chains, 1 H, 1 H, 2 H, 2 H-perfluorodecyl 2-(9-trifluoromethyl-(1 H, 1 H, 2 H, 2 H-perfluoroundecyal))acrylate [1] was successfully prepared. The copolymerization of [1] with methyl methacrylate (MMA) was studied and monomer reactivity ratios were obtained as follows: r(MMA) =2.8±0.5 and r [1]=0at 60°C. The copolymer films of [1] with MMA were examined in wettability and ESCA measurements on their air/solid and mercury/solid interfaces. As to the air/solid interface, an incorporation of a small amounts of the monomer [1] unit in the copolymer was found to make the wettability low steeply, an incorporation of the 0.8∼1.0 mol% monomer unit allowed the wettability of a limiting value as low as that of the homopolym e r film of monomer [1], and further incorporation of monomer [1] unit led to no more change in the wettability. On the other hand, as to the mercury/solid interface, the wettability was found to decrease proportionally with the content of the monomer [1] unit; an incorporation of so small amount of the monomer [1] unit as 1.0 mol% giving no effective change in the wettability from that of polyMMA film. The values in ESCA measurement corresponded well with the results of wettability measurement. It was supposed that the polyfluoroalkyl chains in the copolymers would be selectively and exclusively concentrated and orientated at the air/solid surface region to make it less wettable. In this regard the new fluoromonomer with two long polyfluoroalkyl chains was found to be more effective than the fluoromonomers [1] with one polyfluoroalkyl chain as reported previously.