Polymers derived from fluoroketones. II. Wetting properties of fluoroalkyl acrylates and methacrylates

The critical surface tension of wetting (γc) for certain branched‐chain polymeric fluoroalkyl acrylates and methacrylates was obtained. Polymeric materials utilized in this study can be represented by the repeating units , where R is H or CH3, R′ is H or F, and X is F or Cl, by {article}{empty}{document}-- [ CH₂--- CH( COO( CH₂)ₙ OCF -( CF₃)₂)--]{document} , where n is 2, 5, or 11, and by {article}{empty}{document}-- [ CH₂ --- C( R)( COOCH₂ ( CF₂)n' CF₃)--]{document} , where R is H or CH3 and n′ is 2 or 6. Monomer synthesis involved either the direct acylation of a fluoroketone–metal fluoride adduct or a fluoroalcohol with acryloyl or methacryloyl chloride or a displacement reaction between a fluoroketone–metal fluoride adduct and an ω‐bromoester. In general, modifications in the pendent fluoroalkyl group affected γc in a manner predictable from previous work by Zisman et al.; e.g., γc was increased when either H or Cl was substituted for F in the side chain. In polymeric alkyl acrylates containing a heptafluoroisopropyl side chain γc increased as the fluorocarbon group was removed from the proximity of the polymer backbone by intervening methylene groups. A comparison of the wetting properties of polyacrylates containing either a perfluoroisopropyl or n‐perfluoropropyl group showed that the polymer containing the isopropyl group had a lower γc.