Date of Award

8-2011

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Chemistry

Advisor

Smith Jr., Dennis W

Committee Member

Smith , Rhett

Committee Member

Dieter , Karl

Abstract

Aromatic trifluorovinyl ether (TFVE) monomers are the precursors for perfluorocyclobutyl (PFCB) aryl ether polymers and fluoroethylene/vinylene alkyl/aryl ether (FAE) polymers. PFCB aryl ether polymers are prepared by 2π + 2π cycloaddition of aromatic TFVE monomers. FAE polymers are prepared by nucleophilic addition of dual functional aryl or alkyl alcohols to aryl TFVE monomers. PFCB aryl ether and FAE polymers are amorphous, have excellent processability, high thermal stability, optical clarity, and tunability using a variety of (co)monomers. In this dissertation several novel monomers, polymers, and blends were prepared by incorporation of polyethylene glycol (PEG) or PEG precursors.
Chapter 1 contains the introduction to fluoropolymers and exceptional properties of PFCB aryl ether, FAE, and PEG polymers.
Chapter 2 describes the one step synthesis of macromonomers using diethylene glycol (DEG) and a series of polyethylene glycols (PEGs). Macromonomers were homopolymerized and copolymerized using commercially available TFVE monomers and a PFCB prepolymer. All macromonomers and copolymers were characterized by 1H and 19F Nuclear magnetic resonance (NMR) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Thermal properties of all polymers were determined by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC).
Chapter 3 explores the compatibilization of PEG and a commercial polymer bis(trifluorovinyloxy) biphenyl ether (BPVE) using a copolymer from chapter 2. Reduced interfacial tension was observed by scanning electron microscope (SEM) and phase homogeneity (miscibility) was studied by DSC.
After the one step synthesis of polyethylene glycol (PEG) functionalized with TFVE, a unique crystallization was discovered and is discussed in Chapter 4. DSC analysis and wide angle X-ray diffraction (WAXD) were used to characterize the crystallization of macromonomers.
Chapter 5 details the preparation of a series of PEG-PFCB aryl ether segmented copolymers. Copolymers were polymerized by nucleophilic addition of polyethylene glycol (PEG) to trifluorovinyl ether (TFVE) end-groups of PFCB aryl ether oligomers. Copolymers were linked through a hydrofluoroethane (-CHFCF2-) ether bond. All polymers were well characterized as above. Tgs were studied by DSC analysis and compared to calculated values using the Fox equation.
Polymerization and characterization of novel segmented semiflourinated polyaryl ether (PAEs) were discussed in chapter 6. In addition, thermal properties were explored by DSC and TGA analysis. Surface morphology of semi-crystalline polymers were studied by atomic force microscopy (AFM). Phase images show needlelike crystals. Chapter 7 outlines experimental information.

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