Synthesis of Polyfluoroesters, Polyfluoroamic Acid, Polyfluoroimide, and Polyfluoroacrylates: Formation and Characterization of Their Ultrathin Films

Fluorine-containing polymers were synthesized using three main synthetic approaches: First, polyamic acid (PA-1) and polyimide (PI-1) were produced from direct polycondensation of 4,4‘-hexafluoroisopropylidenediphthalic anhydride and 4,4‘-hexafluoroisopropylidenedianiline in N-methyl-2-pyrrolidinone (NMP). Second, a novel polyester (PEMPFTDE) with fluorine side chains was synthesized from poly(maleic anhydride-co-ethylene). Finally, novel fluorine-containing acrylate (PTFPM) was synthesized by bulk and gas-phase polymerizations. Novel monolayer and ultrathin films of the polymers were prepared by the Langmuir−Blodgett technique. They formed a stable monolayer. The collapse pressure of PA-1 was 62 mN/m, and the area per repeat unit (RU) was 0.12 nm2. The PI-1 has a collapse pressure of 60 mN/m with an area per RU of 0.23 nm2. PI-1 films formed a stable monolayer, too. Multilayer depositions onto substrates were possible for all of the polymers except for PEMPFTDE. LB films were characterized by infrared (IR), ultraviolet (UV), and dielectric constant spectroscopies. Further characterizations were carried out using surface plasmon resonance (SPR) and atomic force microscopy (AFM). The dielectric constant for the PI-1 is 1.5, which is the lowest so far reported to my knowledge.