Applications of the olefin metathesis reaction to the areas of conducting polymers and crosslinked systems were investigated. Metathesis of cis-3,4-dichlorocyclobutene and 3-acetoxycyclobutene was studied with the WCl$\sb6$/SnMe$\sb4$ and Re$\sb2$O$\sb7$/SnMe$\sb4$ catalyst systems to produce processable precursors to polyacetylene. Polymerization of cis-3,4-dichlorocyclobutene with both catalysts yielded a black particulate solid which was characterized as a partially chlorinated form of polyacetylene. Metathesis of 3-acetoxycyclobutene with WCl$\sb6$/SnMe$\sb4$ resulted in the formation of a complex between the metal and the acetate functionality. Metathesis of 1,3-cyclooctadiene to produce an alternating copolymer of acetylene and cyclohexene resulted in negligible amounts of free cyclohexene when run above ceiling temperature conditions for cyclohexene, indicating that 1,3-cyclooctadiene had polymerized predominately via a non-metathesis mechanism. syn-Tricyclo (4.2.0.0$\sp{2,5}$) octa-3,7-diene (TCOD) was synthesized for use as a metathesis crosslinking agent. Solution studies with the WCl$\sb6$/SnMe$\sb4$ catalyst system showed that TCOD could be homopolyerized and also copolymerized with cyclooctene. NMR analysis of the copolymers indicated cyclobutane crosslink junctions. Copolymerization of TCOD with cyclooctene and norbornene using WCl$\sb6$/EtAlCl$\sb2$ gave solid samples which were characterized by swelling and shear modulus measurements. When compared with samples containing TCOD, the control samples (no TCOD) demonstrated a distinct increase in the degree of swelling and a drop in modulus and higher temperatures. Carbon-hydrogen bond activation chemistry was applied to reactions at polymer surfaces to selectively place hydroxyl groups on hydrocarbon polymer surfaces. Four reagents were studied: stannous chloride/oxygen, meta-chloroperbenzoic acid, methanol/benzoylperoxide and trifluoroperacetic acid (TFPAA). Reacted surfaces were analyzed using XPS, ATR-IR, UV, contact angle and gravimetric analysis. The decrease in both the advancing and receding contact angles for the products of each of these reactions indicated an increase in surface energy, and XPS results showed that oxygen had been incorporated onto the surfaces. Kinetics of the TFPAA reaction were studied over a 24 hour period. The reaction proceeded deeply and rapidly($>$1$\mu$m/15 min) to produce a modified surface of hydroxyl and trifluoracetate groups as well as some ketones and non-halogenated ester groups. Base catalyzed hydrolysis, reduction with borane/THF and labeling studies with heptafluorobutyrlchloride showed that the surface-bound functional groups which result from the TFPAA oxidation of polypropylene and polyethylene can act as useful reactive handles for further modification.

Surface dehydrofluorinations of PVF$\sb2$ were examined to prepare "reactive handles" with which to effect further chemical transformations. Surfaces were analyzed by XPS, ATR IR, UV-vis, and contact angles. Using phase transfer catalysis and NaOH, modifications were surface-selective and autoinhibitive (at 40$\sp\circ$C and below), producing eliminated layers (PVF$\sb2$-E) containing some ketones and enols/alcohols. Reaction depths were determined gravimetrically and could be controlled from $\sim$40-100 A with temperature. PVF$\sb2$-E was reactive to nucleophiles, radicals, and electrophiles. The following surfaces were prepared: PVF$\sb2$-OH, PVF$\sb2$-(O)COOH, PVF$\sb2$-Br, PVF$\sb2$-Cl, PVF$\sb2$-NH$\sb2$, PVF$\sb2$-N$\sb3$, PVF$\sb2$-CN, PVF$\sb2$-SH, PVF$\sb2$-SCN, and PVF$\sb2$-Ag$\sp{\rm o}$. Alternatively, reaction of PVF$\sb2$ with DBU produced "patchy", hydrophobic, nearly oxygen-free eliminated surfaces; autoinhibitive kinetics were not observed. Reaction with LDA, KOt-Bu, t-BuLi, and KF/18-crown-6 yielded inferior eliminated substrates for studying surface transformations. Direct chlorination, bromination, or reduction of the PVF$\sb2$ surface was achieved via a cationic mechanism using aluminum chloride (or bromide). Reaction extent depended on the solvent, AlX$\sb3$ Lewis acid strength, temperature, and time. The PVF$\sb2$ surface was completely reduced using the aluminum halide in a heptane/cycloheptatriene mixture. The polyhydrocarbon-like/PVF$\sb2$ composites were oxidized with aqueous chromic acid to produce high surface energy substrates, similar to oxidized polyethylene. PVF$\sb2$ surfaces were modified via aluminum metal vapor deposition and subsequent metal dissolution in either sodium hydroxide or bromine to obtain thinly modified high energy substrates. XPS indicated the introduction of carboxylic acids and/or hydroxyl groups to the outer few angstroms of the substrate with NaOH; carbonyl and bromine groups were formed with net bromine. Surface modifications were used to regulate adsorption phenomena at soluble polystyrene-PVF$\sb2$ interfaces. At low concentrations and low molecular weights, neither polystyrene nor carboxylic acid-terminated polystyrene adsorbed from cyclohexane to PVF$\sb2$; however, adsorption did occur on PVF$\sb2$-NH$\sb2$ or PVF$\sb2$-OH substrates.

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Using X-ray reflectivity, polymers at interfaces are investigated. The absolute coverage and packing of a fluorosurfactant, $\rm F\sb3C(CF\sb2)\sb7$-$\rm SO\sb2N(C\sb2H\sb5)$-$\rm(CH\sb2CH\sb 2O)\sb74CH3$ is determined. We found the coverage to be 34 A$\sp2$/molecule, with the fluorocarbon segments in contact with vapor phase oriented along the surface normal, and the ethylene oxide segments close-packed underneath. However, there is an ambiguity of the orientation of the ethylene oxide segments undetermined. The equation-of-state of end-grafted poly(p-tert-butylestyrene) is determined by varying solvent (toluene) vapor pressure and controlling the temperature. The results are close to mean-field predictions while self-consistent field theory does not prove to be as good a model in this situation. The deviation between the experimental and theoretical results is due to the overestimation of the entropy of mixing between chain segments and solvent molecules, which may be caused by interference from chain stretching. Water swelling in multilayered polyelectrolyte thin films were studied. The thickness changes of the films may be result of the diffusion of water molecules. A full thermodynamic interpretation of the results is still under investigation. As an experimental technique, the x-ray reflectivity method is first reviewed and discussed.

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