Poly(alkylene oxides) containing pendant carboxylate groups separated from the main chain by a spacer-group of eight methylene units were synthesized from functionally-substituted epoxide and 1,3-dioxolane monomers. Ester-substituted oxyethylene polymers of methyl 10,11-epoxyundecanoate and copolymers with various cyclic ethers were prepared in the presence of an aluminumalkyl-water coordination initiator system modified with acetylacetone. Poly(alkylene oxide) ionomers, polyelectrolytes and carboxylic acids were obtained by reactions on the pendant functional groups. The high molecular weight substituted poly(ethylene oxides) were characterized by spectral, thermal and dilute solution measurements. Oxymethylene polymers containing 0.5-2 mole-percent pendant ester groups were synthesized by the cationic copolymerization of trioxane with methyl 10,11-epoxyundecanoate or 4-(1-carbomethoxynonyl)-1,3-dioxolane. A comparative study of the relative reactivities of the ester-substituted monomers with trioxane was made. The substituted 1,3-dioxolane monomer was shown to be more reactive than the substituted epoxide in ring-opening copolymerization with trioxane. Terpolymers of trioxane and 1,3-dioxolane with each of the two functional monomers were also prepared. The functional polyoxymethylenes were characterized by their spectral properties and thermal degradation behavior.

Optically active polychloral was prepared where the optical activity arose exclusively from molecular asymmetry (i.e., helical conformation). Molecular asymmetry requires isotacticity, a high conformational energy barrier for the polymer backbone, and an asymmetric initiator to induce a predominance of one helical screw-sense. Polychloral meets the first two criteria. Asymmetric initiators used to obtain optically active polychloral include tetramethylammonium (+)- or (-)-O-acetylmandelate (TMAAc), tetramethylammonium (+)- or (-)-(alpha)-methoxymandelate (TMA(alpha)M), lithium methyl (+)- or (-)-hydroxidemandelate (LiMM), and lithium cholesteroxide (LiC). Using the above initiators at 0.5 mole % the following maximum specific rotations were obtained for polychloral: TMA(+)Ac initiated {(alpha)}(,D)('25) = -1860, TMA(-) M initiated {(alpha)}(,D)('25) = +210, and Li(-)MM initiated {(alpha)}(,D)('25) = -4760. Optical activity measurements were made in the solid-state due to polychloral's insolubility. Errors in specific rotation were typically 7%. Polychloral initiated by LiC was used as a chromatographic support to obtain 17% resolution of racemic poly((alpha)-methylbenzyl methacrylate). These initiators were mixed with chloral at a temperature greater than pure chloral's ceiling temperature (T(,c) = 58(DEGREES)C). It was generally observed that with either increasing holding times or with higher holding temperatures, prior to cryotachensic polymerization, that polychloral's specific rotation increased. This increase was attributed to the formation of oligomers above T(,c) which help prevent errors in the conformational dyad sequences required for helicity (i.e., g('+)t or g('-)t). Between TMAAc and TMA(alpha)M initiated polychloral there was a nine-fold difference in maximum specific rotation. TMAAc polymer's higher optical activity was attributed to the greater size and polarity of the acetyl group versus the methoxy group in TMA(alpha)M. This resulted in stronger, second order nonbonded interactions between the acetyl group and the polymer's trichloromethyl group, resulting in a greater probability for one helical screw-sense. LiMM initiated polychloral had a specific rotation two times greater than TMAAc initiated polychloral. This increase was attributed to LiMM's asymmetric center being closer to the first trichloromethyl group in the polymer than the TMAAc's asymmetric center resulting in even stronger second order non-bonded interactions to induce molecular asymmetry.

Four monomers, bromodifluoroacetaldehyde (BDFA), chlorodifluoroacetaldehyde (CDFA) and dichlorofluoracetaldehyde (DCFA) have been prepared and polymerized with various cationic and anionic initiators. Monomer synthesis was accomplished through reduction of the corresponding methyl trihaloacetate using lithium aluminum hydride. The trihaloacetates were in turn prepared from methyl trichloroacetate and SbF(,3) and Br(,2) catalyst (DCFA) or SbF(,3) and SbCl(,5) catalyst (CDFA), by methanolysis of the oxidation products of 1,1-dibromo-2,2-difluoroethylene (BDFA and DBFA) or by bromination of chlorotrifluoroethylene followed by treatment with fuming sulfuric acid plus HgO and methanolysis (BDFA). The monomers were all found to polymerize to trihalomethyl substituted polyacetals under a variety of conditions with both cationic and anionic initiators. In contrast to polychloral and polybromochloroacetaldehydes, which are wholly insoluble, it was found that under suitable conditions soluble polymers of relatively low molecular weight could be produced from DBFA, DCFA and CDFA, but not DBFA. Most polymers were, however, insoluble, crystalline and presumably isotactic. Thermal stabilities of all polymers were found to be improved by treatment with either PCl(,5) or acid anhydrides. Degradation was quantitative to monomer. Ceiling temperatures for the polymerizations were found to decrease with increasing bromine content and increase with fluorine content. Monomer boiling points varied in the reverse fashion. Relative polymerization rates were measured through copolymerization with chloral, with isocyanates and with one another. In a separate set of experiments tetrachloroethylene oxide was synthesized by direct oxidation of tetrachloroethylene with oxygen in the presence of ultraviolet light. This preparation resulted in a mixture of tetrachloroethylene oxide and trichloroacetyl chloride in approximately equal amounts under the most favorable conditions. Tetrachloroethylene oxide rearranged readily to trichloroacetyl chloride above 60(DEGREES)C. with an activation energy E(,a) of 3.0 x 10('4) cal/mole and a pre-exponential factor A of 1.9 x 10('13). All attempts to polymerizae tetrachloroethylene oxide under a variety of conditions failed.

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The nature of hydrogen bonding, phase segregation, and hard segment organization is studied in a series of segmented polyurethanes based on hydroxy terminated polybutadiene (HTPBD) soft segments and hard segments consisting of either 2,4- or 2,6-toluene diisocyanate (TDI) and 1,4-butanediol (BDL). The existence of two phase morphology is deduced from dynamic mechanical relaxation and thermal analysis. All polymers exhibit a soft segment glass transition very close to Tg of free HTPBD homopolymer and independent of hard segment structure and concentration. The high temperature transitions, corresponding to the glass transition in 2,4-TDI polymers and melting in the 2,6-TDI polymers are strongly dependent upon hard segment concentration and average hard segment length. Thermal history is found to have negligible effect on the position of the soft segment glass transition and, therefore, in the degree of phase segregation for all materials studied. The time-dependence in dynamic mechanical and thermal properties is related to physical changes within the hard segment domains, independent of the soft segment matrix. An analysis of hydrogen bonding in a selection of HTPBD polyurethanes and model compounds based on 2,4- and 2,6-TDI and p,p'-diphenylmethane diisocyanate (MDI) and BDL hard segments is made using Fourier Transform Infrared Spectroscopy (FTIR). Changes in the frequency, half-width and intensity of the bonded N-H absorption band resulting from thermal treatment are correlated to structural changes as evidenced by differential scanning calorimetry (DSC); variations in behavior are related to differences in packing and the ability and ease at which crystallization and reorganization of the hard segment repeat unit occurs. Resolution of the N-H band into its hydrogen bonded and non-bonded components indicates 80 to 90 percent of the N-H groups are hydrogen bonded at room temperature. Since hydrogen bonded interactions are limited to the hard segment components in PBD-containing polyurethanes, the results provide a quantitative measure of the extent of microphase segregation. Temperature-dependent studies indicate that the onset temperature for hydrogen bond dissociation occurs at 25 to 75(DEGREES)C in the 2,4-TDI polymers and at about 130(DEGREES)C in the 2,6-TDI polymers, close to the transition temperatures for the amorphous and crystalline domain structure, respectively. Heat of dissociation is about 4 kcal/mole for the former series and 7-8 kcal/mole for the latter. Overall, the results indicate that the thermal behavior of hydrogen bonding is sensitive to structure organization and correlate well with other properties studied via calorimetry and dynamic mechanical relaxation.

The microstructure, small and large strain mechanical properties and modes of microstructural failure in one novel and a range of conventional particulate CaCO(,3) polyethylene (PE) composites were investigated by electron microscopy, Instron testing, dilatometry and differential scanning calorimetry. The novel PE-CaCO(,3) composite (63.5 weight % CaCO(,3); M(,w)(' )of PE = 1.5 x 10('6)) used was prepared elsewhere by polymerizing ethylene on catalyst coated filler surface. The conventional PE-CaCO(,3) composites were prepared with a range of PEs (M(,w)(' )=(' )59,000, 200,000 and 2 x 10('6)) and filler content (0, 2, 4, 8 and 19 volume %). Particulate CaCO(,3) (D(,w)(' )=(' )2.5 (mu)m) both with and without titanate coupling agent were utilized. Electron microscopy showed that long range organization of polymer microstructure is not present at levels of filler studied. Radially oriented lamellar growth up to 500 - 1000 nm away is observed at the interface. Dynamic mechanical spectra of unfilled and filled PEs obtained at 11 Hz over the temperature spectrum 100K to 400K revealed that the storage modulus expectedly increases upon introduction of filler. Filler presence decreased tan(delta) in the vicinity of the (gamma)-transition of PE while increasing it at higher temperatures. Complex moduli of model viscoelastic composites were determined using the correspondence principle to explain these observations. Tensile tests showed that yield stress and elongation at break both decreased in presence of filler. Volume dilatation studies revealed that beyond the yield point the presence of filler increased dilatation. Titanate treatment of filler suppressed the dilatation observed. Scanning electron microscopy studies of specimens undergoing deformation revealed formation of void-fibril microfailure zones which resemble crazes. Another area of investigation was the diffraction contrast imaging of thin PE films in the electron microscope. Image contrast is shown to arise from differential diffraction efficiency of differently oriented lamellae. Development of new scanning transmission electron microscopy imaging techniques permitted observation of multiple bend contours arising from curvature of lamellae and consequently estimation of lamellar dimensions.

Head-to-head (H-H) polyisobutylene was prepared by a Grignard/alkylbromide coupling polymerization using 2,2,3,3-tetramethyl-1,4-dibromobutane as the monomer. The coupling polymerization was carried out at -5 to -10(DEGREES)C in a mixture of benzene and tetrahydrofuran solvent using copper (I) salts as catalysts. The H-H polyisobutylene obtained was found to have bromine end groups and number-average molecular weights of 3,000 to 10,000. The polymer showed interesting crystalline and thermal properties especially in comparison to head-to-tail (H-T) polyisobutylene. H-H polyisobutylene was found to be approximately 50% crystalline under normal conditions, with a melting point of 185-189(DEGREES)C and a glass transition at 85(DEGREES)C. H-H polyisobutylene thermally degrades at 315(DEGREES)C which is some 65(DEGREES)C lower than H-T polyisobutylene under inert atmosphere. Initial studies show that the bond between the two quaternary carbons of the H-H link is the first to break. Blending of the H-H and H-T polyisobutylene was found to yield a two-phase incompatible system as determined by DSC studies. Poly(1,1-dimethylpropane) was prepared from 2,2-dimethyl-1,3-dibromopropane by a sodium Wurtz polymerization. The Grignard/alkylbromide coupling polymerization was determined to be ineffective for this dibromide. The polymer obtained had a glass transition temperature of -17(DEGREES)C and melted between 70 and 90(DEGREES)C. The thermal properties of poly(1,1-dimethylpropane) were compared to those of H-H and H-T polyisobutylene and found to be intermediate between the two. The copolymerization of 3,4-dimethyltetrahydrofuran with selected cyclic ethers was also studied. It was found that although 3,4-dimethyltetrahydrofuran did not homopolymerize under the conditions used in this study, it did readily copolymerize with propylene oxide and epichlorohydrin. The initiator used was PF(,5) and 1:1 copolymers of 3,4-dimethyltetrahydrofuran and either epoxide were obtained. The reactivity ratios for the copolymerization of 3,4-dimethyltetrahydrofuran and epichlorohydrin were found to be r(,1) = 0.22 (+OR-) 0.05 and r(,2) = 0.11 (+OR-) 0.01 respectively. This gave strong indication of an alternating copolymer.

Developing new syntheses for high energy polymers by attaching nitro groups to preformed polymers and characterizing these polymers are the objectives of this work. Our efforts have been directed toward two overall strategies. They are (a) nitromercuration followed by demercuration and (b) nitroiodination followed by dehydroiodination or deiodination. Both are illustrated below for a trans-1,4-butadiene unit. Application of the nitration method reported by Corey and Estreicher to diene polymers fails owing to the insolubility of the hydrophobic polymers in the aqueous nitromercuration reagents. Use of water immiscible organic cosolvents gives slow nitromercuration with substantial amounts of nitrate esters formed. To overcome these problems, a non-aqueous phase transfer catalyzed method for rapid selective nitromercuration of diene polymers, poly(cis-1,4-butadiene), hydroxy-terminated polybutadiene, and carboxy-terminated poly(butadiene-co-acrylonitrile), has been developed. Conducting the dinitrogen tetroxide - alkene reaction in ether in the presence of iodine has been found to produce (beta)-nitroalkyl iodides which can be transformed into either nitroalkenes or nitroalkanes easily when treated with base or reducing agent, such as sodium borohydride, respectively. The simple alkenes, cyclohexene, 1-hexene, and 2-hexene, we investigated undergo facile nitroiodination-dehydroiodination to give nitroalkenes in good yields. Hydroxy-terminated polybutadiene gives significant amounts of nitrate ester functionalities for nitroiodination in both ether and tetrahydrofuran. Reductive deiodination as well as base dehydroiodination have been studied for the nitroiodinated polymer substrates.