The dynamics of the reduction of graphite oxide by tetralin and 9,10-dihydroanthracene was studied using MAS NMR and elemental analysis. The reductive activity of 9,10-dihydroanthracene is so high that graphene-like hydrocarbon particles may be obtained with O/C atomic ratio equal to 0.03.

It was shown that the structure of graphite oxide is formed in two stages. The first is hydroxylation of the graphene layers to a level of 4–6 hydroxyls to one coronene fragment (C 24 ). The second is the accumulation of hydroxyl, peroxide, and hydroperoxide groups, accompanied by strong dearomatization of the graphene structure. Epoxide groups, previously considered some of the main oxygen-containing functional groups in graphite oxide, were not detected.

Effect exerted by the synthesis conditions of residual graphite nitrate in the system concentrated nitric acid-glacial acetic acid-water on the properties of the final product was studied in wide consumption range of the reagents. The optimal ratio of the reagents was determined. The dependence of expansion coefficient on the loss of mass by the expanded product was determined.

The formation of residual graphite nitrate on keeping in air and the properties of this material were studied in relation to the amount of nitric acid taken for the graphite treatment. The dependence of the expansion ratio on temperature and on the extent of the graphite oxidation was examined. The acidity of the final product was studied in relation to the nitric acid consumption in the final step of the graphite oxidation.

The authors have studied the joint liquefaction of sulfurous brown and long-flame coals of Ukraine and polyethylene and polypropylene at 430 °C and an initial pressure of up to 5.0 MPa. The gas phase consisted of H 2 , CO 2 , Ar or H 2 + CO 2 . The total conversion of the mixture and the volatile-matter yield from the residue of joint liquefaction after extraction of the products by alcohol-benzene were determined. The observed overall effect of synergism varied from 0 to 30%, depending on the type of polyolefin, coal and gas medium. Tetralin and H 2 inhibit the decomposition of polyethylene, which is why the individual effects of synergism may be either positive or negative.

The reductive alkylation of a French petroleum asphaltene (Lagrave) was studied with potassium in THF, in absence of an electron transfer reagent. From the number of butyl and benzyl groups added to the starting asphaltene, the difference of reactivity of the alkyl reagents, butyl iodide and benzyl bromide, was pointed out. Special attention was focused on the cleavage of C–S and C–O linkages in relation to the structural modifications. From the number of hydrogen atoms added during the reduction step, it was concluded that the sulphide linkages are mainly of aryl-S-aryl, aryl-S-alkyl or alkyl-S-alkyl types. The TLC-FID (Iatroscan) analysis was found to be very suitable to follow the “depolymerization” process of the asphaltene, qualitatively as well as quantitatively, by the application of quantitative hydrocarbon group type analysis.

Alkyation modification is an attractive procedure for the loosening of intermolecular forces that contribute to the binding of coal molecules in solid state. This concerns a basic reagent (n-BuLi/TMEDA) use to promote the non-reductive (C-alkylation) of coal with an alkyl halide (n-BuI). Carboniferous coal, C = 84.8%, was activated by alkali metal treatment and subjected to "ionic" oxidation and subsequent alkylation. Products of reactions were 60-84% soluble in CHCl3, depending on activation procedure (Sternberg, Miyake or Lazarov). Spectral characteristics, i.e. FTIR, H-1 and C-13 CP/MAS NMR spectra of soluble portions and residues, were measured. The "number average" structural parameters were calculated and mean statistical molecules were compared. The data gave us ground to assume that the effect of C-alkylkation was enhanced by portion acidity increase. Structures containing C-H bonds adjacent to electron-withdrawing substituents were arranged by "ionic" oxidation. By introduction of 4CO functions per 100 carbon atoms (COOH and CO groups) the number of reactive sites was increased and, respectively, the number of alkyl groups added reached similar to 9 Bu/100 C. On the base of spectral data a set of parameters for "unsubstituted" units were deduced. Similarities in the "average" parameters for solubilized coal and molecular characteristics of extractable portions were registered.

Chloroform soluble portion of N,N-dimethylacetamide (DMAA) extract of bituminous coal from Donbass deposit was subjected to detail study by spectral (IR, NMR, MS) and chromatographic (GPC) methods. On this base the product was characterized by bulky and molecular parameters. Chloroform extract was considered as a simplified coal model and its behaviour in the course of alkylation (reductive and non-reductive after "ionic" oxidation) was comparatively studied. The extract and the products of modifications were divided in "narrow" fractions and characterized by spectral methods. Distributions in Z series (hydrogen deficit) determined by MS were performed. By following of Z, Z(N) and Z(NO) series a salient difference in alkylation was revealed.

Oxidation of aromatic hydrocarbons and their heterogeneous analogous reduced by potassium in solvating media was studied. These compounds were selected as models of coal organic matter. The main idea was to try to find an analogy in the bahaviour of model compounds and coal molecules in the processes of reductive modification. Our results has confirmed the observation that some aromatic hydrocarbons regenerate their initial structure. Reactions of protonization, oxidation and dimerization depending on the compound chemical character were registered, as well. There were some spectral evidences for the splitting of covalent C-C links. In the same condition alkaline metal cation was oxidized to the corresponding superoxide, KO2.

The influence on its thermal behaviour of the structural modifications afforded to a bituminous coal by several chemical treatments (reduction, alkylation, oxidation followed by butylation) was studied by thermogravimetry (TGA) and oxidative pyrolysis (Ox-Py). The results were discussed in relation to the structural information already obtained by infrared spectroscopy and with the rheological properties characterized by thermomechanical analysis. These results pointed out that the classical behaviour of the bituminous coal is highly modified after chemical treatments. For example, the weakening of the intermolecular interactions, after alkylation, is evidenced by the increase of the weight losses between 180 and 800 degrees C (up to 90-95% after O-butylation).

The modifications afforded by several chemical treatments to the main functional groups of a bituminous coal were characterized by diffuse reflectance infrared spectroscopy. The starting materials were the polyanions and potassium coal adducts obtained from the parent coal, treated with potassium according to the Sternberg and Lazarov reactions. The results show the differences in the reactive sites involved in these reactions and in the behaviour of these sites during protonation or alkylation. Some of the typical functional groups introduced (or modified) can be active acceptor sites during hydrogen transfer from tetralin at low temperature (315°C) in conditions avoiding thermal bond cleavage. Taking into account the semiquantitative results of the i.r. analysis, the participation of several active sites in the total hydrogen transfer was estimated, indicating the role of quinonic, aromatic and alkyl groups.

The possibility in principle of using the products of extraction of native lignites and hard coals. entbituminized lignites, and chemically modified hard coals as efficient inhibitors of metal corrosion in acidic media is shown. The introduction into known industrial corrosion inhibitors of small additions of coal extracts considerably boosts the inhibiting activity with low concentrations of the inhibitor and elevated temperatures. The degree of protection of metals with the aid of such inhibitors exceeds the anticorrosion characteristics of their separately taken components and is 80-90%.

A procedure for the extraction, separation and characterization of coal bitumen is described. A Carboniferous coal was subjected to exhaustive (single-step) extraction with dimethylacetamide (DMAA) at ambient temperature. The treatment solubilized ∼24 wt% of the organic matter. The bitumen was fractionated further and some fractions were separated into normal and branched/cyclic components. By g.c. and g.c.-m.s., n-alkanes, hopanes, benzohopanes, steranes, bicyclic sesquiterpanes, seco-hopanes, polycyclic aromatic hydrocarbons, and their alkylated homologues were identified. Number-average structural analysis was applied to the polar fractions and revealed some peculiarities of the structural units, i.e. simple molecular aggregates.

The rheological behaviour of a Donbass bituminous coal was characterized by thermomechanical analysis under high pressure (6 MPa) from ambient temperature up to 600°C. Under these conditions the onset of the transfer of the coal from a viscous to a viscofluid state could be determined from the thermomechanical curves in a range of temperature not easily accessible with classical plastometers. The softening temperature and the activation energy of the viscous flow could also be determined. As intramolecular interactions are principally involved in the first stage of the thermoplasticity of coals, chemical modifications were applied to the coal by reductive alkylation and oxidation under several conditions (Sternberg and Lazarov reactions) to modify the intermolecular association. The influence of these treatments is clearly shown by the thermomechanical analysis.

Hydrocarbon subfractions of a Carboniferous bituminous coal extract were subjected to compound-specific isotope analysis (CSIA). The carbon isotope compositions of individual n-alkanes, isoprenoids, aromatic hydrocarbons and triterpenoids were determined to provide supplementary confirmation for the biomarker sources as deduced from their molecular structures. The total bitumen extract has a δ13C value of −25.03‰. The δ13C data for the biomarkers fit an origin from higher plants with a minor contribution from microbial activity.

The chloroform soluble portion of dimethylacetamide extract from a subbituminous coal was subjected to different types of chemical modification, i.e. reduction. reductiVe alkylation, non-reductive alkylation, 'ionic' oxidation with subsequent alkylation. etc. The products of the reactions were studied by spectral and chromatographic methods. An increase in molecular mass. prevailing over degradation, was registered by gel permeation chromatography (g.p.c.) analysis.

A method of extending substantially the information obtained from e.p.r. spectra for bituminous coal is suggested. During reduction with subsequent alkylation or oxidation, the level of polydispersity of paramagnetic structures in coal organic matter was found to increase. Evidence for mutual influence of coal paramagnetic centres responsible for narrow and broad signals in the e.p.r. absorption spectra was also obtained.