| Synthetic methods for incorporating preformed polymers into several layered inorganic host lattices to form nanocomposites have been investigated and the results obtained are described. The nanocomposites contain an ordered arrays of interacting polymer and inorganic phases, where at least one dimension is in the nanometer size range. A general overview of the science of nanocomposite materials is presented in Chapter 1.; A template method has been developed for inserting anionic vinyl polymers, including poly(acrylic acid), poly(vinylsulfonate) and poly(styrenesulfonate), in between positively charged sheets of layered double hydroxides (LDHs) {dollar}rm Msb{lcub}1-x{rcub}Alsb{lcub}x{rcub}(OH)sb2sp+{dollar} (M=Mg, Ca, Co) and {dollar}rm Znsb{lcub}1-x{rcub}Msbsp{lcub}x{rcub}{lcub}prime{rcub}(OH)sb2sp+ (Mspprime{dollar}=Al, Cr) to form layered nanocomposites. Structural and microstructural development, compositional details, and thermal characteristics of the nanocomposites were studied by X-ray diffraction (XRD), FT-IR spectroscopy, elemental analysis, differential scanning calorimetry (DSC), thermogravimetry (TG), and scanning and transmission electron microscopy (SEM/TEM).; Conventional exfoliation-adsorption methods have been extended to the preparation of nanocomposites of linear poly(ethylenimine) (LPEI) with several host lattices. The products exhibit lattice expansions along the stacking direction of 3.9-4.7 A and polymer contents of 13-18 mass percent, consistent with an adsorbed monolayer of LPEI between host sheets. Results are compared with the poly(ethylene oxide) PEO analog and are rationalized in terms of an energetic model for nanocomposition.; A method has been developed for the quantitative removal of polymers such PEO from the interlayer space of several host lattices. It involves the reaction of the nanocomposites with aqueous tetraethylammoniun salts under ambient conditions. Detailed characterization of solid reactants and products by XRD, TG, FTIR, gel permeation chromatography (GPC), and elemental analysis indicate that these displacement reactions go to completion without polymer degradation after initial formation of the nanocomposites. Kinetic results are presented and a reaction mechanism is proposed based on observed trends.; New synthetic methods including latex-colloid interaction and intragallery chemical conversion of precursor polymers developed for preparing nanocomposites containing conjugated polymers such as poly(pyrrole), poly(thiophene) and poly(phenylenevinylene) (PPV) are described. Products obtained are characterized by XRD, SEM, FTIR, TGA and electrical conductivity. Results on the nanocomposition of polyacetylene ionomer, poly(phenylene sulfide) (PPS), and its copolymer-poly(phenoxyphenylene sulfide) using exfoliation-adsorption and melt intercalation process are also presented. |
