A. V. Grachev

Interactions of sodium liquid glass with triethylammonium decahydro-closo-decaborate (Et3NH)2B10H10

Reactions of sodium silicates of liquid glass (LG) with closo-triethylammonium decaborate (Et3NH)2B10H10 were studied over a wide range of component ratios LG/(Et3NH)2B10H10 of 95/5, 85/15, 70/30, 60/40, 50/50, 40/60, and 26/74 wt/wt. IR spectroscopy showed that the introduction of anion into the LG gives rise to the formation of a three-dimensionally branched system of multicenter bonds:

Composite materials based on fluoropolymers and oxyfluoride glasses

B - H^{\delta - } \cdots H^{\delta + } - O - H^{\delta + } \cdots O^{\delta - } - Si

Thermal oxidation of the decahydro-closo-decaborate anion B10H102− in a silicate matrix

and

Thermal and thermo-oxidative properties of the decahydro-closo-decaborate anion B10H102− in a silicate matrix

B - H^{\delta - } \cdots H^{\delta + } - O \cdots H - O - H \cdots O^{\delta - } - Si

A hybrid resin based on organoelement and inorganic oligomers

and, in fact, to the formation of an inorganic polymer in the reaction solution. Studies of the thermal stability limits of closo-decaborate anion in LG/B10H102− compositions showed that the LG silicate matrix modified with anion B10H102−(40/60) is stable up to 500°C.

Composites based on triethylammonium dodecahydro- closo -Dodecaborate (( Et 3 NH) 2 [B 12 H 12 ]) and sodium silicate water glass

It was shown that molded specimens of polymer composite materials can be obtained by an extrusion method by melt blending of Fluoroplast F-2 MB (modified poly(vinylidene difluoride)) and oxyfluoride glasses of the composition 3B2O3 (40SnF2–30SnO–30P2O5). The compositions of the observed phases of the composites were determined. Conclusions were made on the incompatibility of the components, their dispersion distribution, and strong adhesion interaction. Data on the nano level of the blending of the components were obtained. The elongation and Brinell hardness were measured in the composites with various (0–50 vol %) oxyfluoride contents. It was concluded that it is possible to produce composites based on fluorinated hydrocarbon and fluoroxide polymers.

Features of the melt flow of polyethylene and boron oxide oligomer blends

We have studied the thermal oxidation of composites produced by reacting sodium water glass with the B10H102− anion owing to multicenter contacts and possessing a spatially branched structure. The results demonstrate that, in air between 300 and 500°C, some of the decahydro-closo-decaborate anions present in the water glass/B10H102− system oxidize, which is accompanied by a large exotherm and leads to the formation of a surface borosilicate layer preventing further oxygen diffusion into the bulk of the sample and oxidation of the B10H102− anion. Samples protected by a coating produced during thermal oxidation possess thermal and deformation stability up to 600°C.

Optically transparent heat-resistant nanocomposites based on epoxy resin and silicon dioxide

Using thermogravimetric analysis and differential scanning calorimetry in air and argon, we have studied the products of reactions between the B10H102− anion and water glass (WG) sodium silicates. The reaction products have the form of spatially branched supramolecular structures. Supramolecular structures of various compositions have been synthesized at initial WG/(Et3NH)2B10H10 reactant ratios of 70/30, 60/40, 50/50, and 40/60. In the range 20–600℃, we have studied the following processes in the WG/B10H102− systems: removal of adsorbed water (50–200℃), condensation of silicates containing silanol groups (200–300℃), and oxidation of the B10H102− anion in the silicate matrix (300–600℃). All three processes have been shown to depend on content.

Hybrid complex polymers of boron and imidazole hydroxide

Organic resins have important disadvantages: the combustibility and toxicity of the degradation products that evolve during thermal action. In this context, the synthesis of reactive low-viscosity resins depleted in hydrocarbon groups is of great interest. A hybrid resin has been prepared via the mutual dissolution of the reactive organosilicon oligomer methylmethoxysiloxane and a boric acid oligomer. The reaction proceeding between the components has been confirmed by thermogravimetric measurements, analysis of volatiles, and 13C NMR spectroscopy data obtained at different stages of the process.

Polycomplexes of the polycondensation products of boric acid and p-phenylenediamine

The [B12H12]2– anion, a three-dimensional aromatic system with a uniform electron density distribution over its boron skeleton, has been shown to react with sodium silicate water glass (WG) to form a supramolecular structure. The WG/[B12H12]2– system has both short-range and weaker, long-range contacts, which influences the chemistry of the thermolysis process and, as a consequence, the thermal and thermomechanical properties of the composites. At 60% (Et3NH)2[B12H12] in the starting mixture, the reaction products contain ~6.6% [B12H11NEt3]2–, a substituted derivative that has a plasticizing effect in the case of thermomechanical processing. At an optimal ratio of the starting reagents, the thermo-oxidative stability of the [B12H12]2– anion and the deformation resistance of the WG/[B12H12]2– system persist up to 600°C.