Journal of Applied Polymer Science, Vol.74, No.8, 2029-2038, 1999
Synthesis of urethane craft copolymers with perfluoroalkyl and silicone-containing side chains and their surface properties
Dihydroxyl-terminated macromonomers with two groups, a perfluoroalkyl group and a silicone-containing group, were synthesized by free-radical polymerization with perfluoroalkylethyl acrylate (FA), 3-[tris(trimethylsilyloxy)silyl] propyl methacrylate (SiMA), and 1-thioglycerol (TG). Using these macromonomers and toluene-2,4-diisocyanate (TDT), various urethane graft-co-(septadecafluorodecylacrylate)-(trimetylsiloxy silylpropyl acrylate) copolymers (PUFSGs) with differing FA and SiMA contents were synthesized. The macromonomers and PUFSGs synthesized were characterized and identified by GPC, DSC, (X-ray photoelectron spectroscopy (XPS), FTIR, and H-1-NMR analysis. The surface free energies of PUFSGs, 9-12 dynes/cm, depend strongly on FA content but not on SiMA content. The glass transition temperature of PUFSG is strongly dependent on SiMA content. The perfluoroalkyl group originating from FA is preferentially arranged to the outermost layer at the air-polymer interface to the silicone-containing group originating from SiMA. The surface free energies of PUFSG/polyvinyl chloride (PVC) blends exhibit extremely low values, 10-14 dynes/cm, indicating that extreme segregation of PUFSG occurs at the air-polymer interface. Most PUFSGs added to PVC are located at the air-polymer interface, and PUFSGs are very effective in lowering the surface free energy.