Applications of perfluorocyclobutyl(PCFB) aryl ether polymers and acrylonitrile based materials

This dissertation focuses on the applications of various materials and their synthesis based on fluorocarbons and acrylonitrile. These materials include statically non-wetting surfaces, proton exchange membranes for fuel cells, and carbon fiber precursors. Perfluorocylobutyl aryl ether (PFCB) polymers provide a unique platform to develop materials for different applications. They are solution processable which makes their industrial manufacturing cost low. This is only one of the many advantages of using these polymers. These polymers are used to make statically non-wetting surfaces through electrospinning. Electrospinning is a well-known instrumental technique used to generate nanoscale fibers with high surface area to volume ratio. Statically non-wetting surfaces are the surfaces which are highly hydrophobic surfaces (Water Contact Angle (W.C.A) ≥150°). These kinds of surfaces are significant in collecting waters in arid areas, microelectronics and other applications. There are two ways to generate highly hydrophobic surface of PFCB through electrospinning, they are as follow: either to increase the fluorine concentration on the surface, or to add some external agent to induce more roughening on the surface. In our work we have produced statically non-wetting surfaces (W.C.A ≥150°) of biphenyl-perfluorocylobutyl aryl ether (BP-PFCB) polymer through optimization of electrospinning parameters and by electrospinning a solution of BP-PFCB with very small amount (1.5 wt %) of 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIm-PF6). BMIm-PF6 induces roughening to promote hydrophobicity as observed by the AFM. These surfaces were characterized by AFM, ATR-IR, SEM and EDX.;These PFCB polymers can be sulfonated to give materials which can be used as proton exchange membrane (PEM) for fuel cells. A blend of the block copolymer of sulfonated perfluorocylobutyl aryl ether (s-PFCB) and perfluorovinylsulphonylimide- co-tetrafluoroethylene (PFVSI-TFE) was used to make membranes for fuel cells. The PEM made from these blends show high proton conductivities in the range of 110-114 mS/cm at 80°C (100% relative humidity) and shows good thermal stability.;In the later section of this dissertation we described acrylonitrile, N-vinyl imidazole, and various monomers-based terpolymers and the influence of incorporating the third monomer on glass transition temperature and oligomerization temperature. The various monomers included are vinyl acetate, n-butyl acrylate and acrylamide. Vinyl acetate and n-butyl acrylate are used to lower the glass transition temperature of the polymer. By the addition of the butyl acrylate unit a 25 °C change in the glass transition temperature was observed. This change is less pronounced when vinyl acetate was incorporated (DeltaT g=10°C).