Acrylic Copolymers with Perfluoroalkylated Biphenyl Side Groups: Correlation Structure−Surface Properties

Abstract

We investigate the surface properties of a series of random copolymers of perfluoroalkylated biphenyl acrylates (CH2CHCOO(CH2)mOC6H4C6H4O(CH2)3C8F17, m = 0, 6, 11) and methyl methacrylate (MMA) or octadecyl methacrylate (SMA). The surface properties of the polymers were correlated to the structural parameters. Wetting hysteresis and surface tensions were estimated from dynamic contact angle measurements. It was established from atomic force microscopy analysis that wetting hysteresis cannot arise from surface anomalies. The stability of the polymer surface is enhanced by the presence of biphenyl groups and octadecyl side chains in SMA copolymer series. Surface tensions of polymers were calculated using different methods involving the Lifshitz−van der Waals/acid−base approach (van Oss et al.) and the equation of state (Neumann et al.). The low surface tensions (ca. 11 mN/m) depend on three main structural parameters: copolymer composition, type of comonomer, and length of hydrocarbon spacer (CH2)m.