Synthesis and characterization of poly(dimethylsiloxane)-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) diblock copolymers with low surface energy prepared by atom transfer radical polymerization

Well-defined poly(dimethylsiloxane)-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) (PDMS-b-PHFBMA) diblock copolymers are synthesized via atom transfer radical polymerization (ATRP). The chemical composition and structure of the copolymers are characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and molecular weight measurement. Gel permeation chromatography (GPC) is also used to study the molecular weight distributions of the PDMS-b-PHFBMA diblock copolymers. The microstructure of the resulting copolymers is investigated by transmission electron microscopy (TEM). The results of TEM show that the diblock copolymers are microphase-separated if the bulk contains enough PHFBMA segments. The effect of fluorine content on the surface energy and the bulk structure is investigated by static water contact angle. Surface energy of PDMS-b-PHFBMA films is indirectly obtained from contact angle.