Highly wettable polyethylene films generated by spontaneous surface enrichment of perfluoroalkylated phosphorylcholines

Abstract

We report here a new feature for highly wet-table polyethylene films prepared by spontaneous surface enrichment of perfluoroalkylated phosphorylcholine (PC) additives via a simple heat-press technique. Perfluoroalky-lated PCs were newly synthesized from monohydroxyethyl ether compounds with hexafluoromethylene (C6F13PC), octafluoromethylene (C8F17PC), and decafluoromethylene (C10F21PC) chains. Hexadecyl phosphorylcholine (C 16PC) was synthesized as a control. These PC additives were mixed well with low-density polyethylene (LDPE) microparticles (Φ = 6 μm), placed between stainless plates, and pressed at 120°C. Perfluoroalkylated PCs effectively improved the surface wettability of the composite film compared with that of the alkylated PC. C8F17PC is extremely surface active in the LDPE matrix and occupies ∼ 95% of the outermost ∼ 10 Å. The water contact angle data for the LDPE film was decreased from 94°/81° (θA/θR) to 28°/8° by the addition of an approximately low concentration of C8F 17PC (3.3% w/w) because of spontaneous enrichment on the surface. When the elongation to break value of the films was slightly reduced with the PC additives, Young's modulus and the tensile strength of the composite films were similar to those of pure LDPE film. In conclusion, fluoroalkylated PCs have good potential as additives to improve the wettablility of thermoplastic polymers. © 2006 Wiley Periodicals, Inc.