Ion-containing block copolymers blend ionic liquid properties with well-defined polymer architectures. This provides conductive materials with robust mechanical stability, efficient processability, and tunable macromolecular design. Conventional free radical polymerization and anion exchange achieved copolymers containing n-butyl acrylate and phosphonium ionic liquids. These compositions incorporated vinylbenzyl triphenyl phosphonium and vinylbenzyl tricyclohexyl phosphonium cations bearing chloride (Cl), or bis(trifluoromethane sulfonyl)imide (Tf2N) counteranions. Differential scanning calorimetry and dynamic mechanical analysis provided corresponding thermomechanical properties. Factors including cyclic substituents, counteranion type, as well as ionic concentration significantly influenced phosphonium cation association. 1, 1\'-(1, 4-Butanediyl)bis(imidazole) neutralized NexarTM sulfonated pentablock copolymers and produced novel electrostatically crosslinked membranes. Variable temperature FTIR and 1H NMR spectroscopy confirmed neutralization. Atomic force microscopy and small angle X-ray scattering studied polymer morphology and revealed electrostatic crosslinking characteristics. Tensile analysis, dynamic mechanical analysis, thermogravimetric analysis, and vapor sorption thermogravimetric analysis investigated polymer properties. The neutralized polymer demonstrated enhanced thermal stability, decreased water adsorption, and well-defined microphase separation. These findings highlight NexarTM sulfonated pentablock copolymers as reactive platforms for novel, bis-imidazolium crosslinked materials. 4-Vinylbenzyl piperidine is a novel styrenic compound that observably autopolymerizes. In situ FTIR spectroscopy monitored styrene and 4-vinylbenzyl piperidine thermal polymerizations. A pseudo-first-order kinetic treatment of the thermal polymerization data provided observed rate constants for both monomers. An Arrhenius analysis derived thermal activation energy values. 4-Vinylbenzyl piperidine exhibited activation energy 80 KJ/mol less than styrene. The monomer differs from styrene in its piperidinyl structure. Consequently, in situ FTIR spectroscopy also monitored styrene thermal polymerization with variable N-benzyl piperidine concentrations. Under these circumstances, styrene revealed activation energy 60 KJ/mol less than its respective bulk value. The similarities in chemical structure between styrene and 4-vinylbenzyl piperidine suggested thermally initiated polymerization occurred by the Mayo mechanism.  The unique substituent is proposed to offer additional cationic effects for enhancing polymerization rates. Living anionic polymerization of 4-vinylbenzyl piperidine achieved novel piperidinyl-containing polymers.  Homopolymer and copolymer architectures of this design offer structural integrity, and emphasize base stability.  Sequential anionic polymerization afforded a 10K g/mol poly(tert-butyl styrene-co-4-vinylbenzyl piperidine) diblock and a 50K poly(tert-butyl styrene-co-isoprene-co-4-vinylbenzyl piperidine) triblock. Alkylation studies involving a phosphonium bromide salt demonstrated the future avenues for piperidinium based polymer designs. These investigations introduce piperidinyl macromolecules as paradigms for a new class of ammonium based ionic materials. / Master of Science

The synthesis and characterization of a variety of ammonium ionenes from water-soluble coatings to high-performance elastomers are discussed. Water-soluble random copolymer ionenes were synthesized using the Menshutkin reaction from 1,12-dibromododecane, N,N,Nâ ²,Nâ ²-tetramethyl-1,6-hexanediamine, and 1,12-bis(N,N-dimethylamino)dodecane. The absolute molecular weights were determined for the first time using a multiangle laser light scattering detector in aqueous size exclusion chromatography and the weight-average molecular weights of these ionenes were in the range of 17,000-20,000 g/mol. Charge density increased with increasing molar ratio of N,N,Nâ ²,Nâ ²-tetramethyl-1,6-hexanediamine and the glass transition temperature (Tg) increased from 69 °C to 90 °C as the charge density increased. Small angle x-ray scattering (SAXS) showed isotropic scattering patterns for these ionenes. A limited study on cytotoxicity of these ionenes showed no direct correlation between charge density and cell viability for human brain microvascular endothelial cell line. A series of low hard segment (HS) content, poly(propylene glycol) (PPG)-based ammonium ionenes were synthesized using a Menshutkin reaction from bromine end-capped PPG oligomers (prepared using acid-chloride reactions) and N,N,Nâ ²,Nâ ²-tetramethyl-1,6-hexanediamine. Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry, titration analyses, and ¹H NMR spectroscopy, confirmed the difunctionality of bromine end-capped PPG oligomers. Thermal analysis revealed Tg's of -60 °C, comparable to pure PPG, using differential scanning calorimetery (DSC), dynamic mechanical analysis (DMA) confirming microphase separation, and an onset of degradation (Td) at 240 °C. Synthesis of a series of random block copolymer ammonium ionenes with an aliphatic 1,12-dibromododecane as part of the hard segment (33 wt% HS) enhanced film formation and supported microphase separation property. The Td and Tg did not change compared to PPG-ionenes with lower HS content. DMA and tensile testing demonstrated the influence of soft segment (SS) molecular weight and hard segment (HS) content on the mechanical properties of segmented ammonium ionenes. DMA showed the onset of flow, ranging from 100-140 ºC for 1K and 2K g/mol PPG-based ionenes respectively. SAXS revealed a Bragg distance scaled with soft segment molecular weight and ranged from 6.6 to 23.4 nm for 1K to 4K g/mol PPG-based ionenes, respectively. An investigation of the salt-responsive solubility property of random block copolymer PPG-ionenes revealed a dependence on PPG molecular weight. The 1K g/mol PPG-based ionenes with a hydrophilic (HPL)/hydrophobic (HPB) value ranging from one to three showed solubility in both water and one wt% NaCl aqueous solutions. The 2K g/mol PPG-based ionenes containing HPL/HPB value of two to 15 showed cloudy dispersions in water and one wt% NaCl solutions. The 4K g/mol PPG-based ionenes possessed the salt-responsive character; 4K g/mol PPG-based ionenes with HPL/HPB values of one to 12 showed milky dispersions in water, suspended particles in one wt% NaCl solutions and film precipitation at a HPL/HPB molar ratio of 19. / Master of Science