Composites on Base of the Ultradispersed Polytetrafluoroethylene and Graphite Oxide Intercalated Compounds

Composites based on ultradispersed polytetrafluoroethylene and intercalated graphite oxide compounds with dodecahydro-closo-dodecaborates and methods of their fabrication have been developed. The fabricated composites have been characterized using XRD analysis, and optical microscopy. These composites are distinguished with completeness of their combustion, since the combustion products comprise gaseous boron fluorine-containing compounds of boron, boron trifluoride (BF3), and boron oxyfluoride ((BOF)3). Besides, these composites are characterized with increased energy capacity as compared to purely oxygen-containing compounds, since the heat of formation of boron fluorine-containing compounds is higher than that of boron oxide. Introduction of ultradispersed polytetrafluoroethylene imparts composites with hydrophobicity, thus improving their functioning properties.

Composites on Base of the Ultradispersed Polytetrafluoroethylene and Chitosan Salts

Composites based on ultradispersed polytetrafluoroethylene and chitosan salts (nitrate, perchlorate and dodecahydro-closo-dodecaborate) and methods of their fabrication have been developed. For this purpose, the ultrasonic effect on the mixture of the aqueous gels of chitosan salts with dry UPTHE or UPTFE ethanol dispersion with propeller agitators. Introduction of ultradispersed polytetrafluoroethylene improving their functioning properties, namely high combustion efficiency and resistance to air moisture.

Preparation of Ethyl 4-Nitrobenzoate Using Ultradispersed Natural Zeolite Catalysts, Ultrasound and Microwave Irradiation

The new possibilities of preparing the ethyl 4-nitrobenzoate by esterification of 4-nitrobenzoic acid (4-NBA) with ethanol under argon at 80°C are shown;particularly, over catalysts: on micrometric (4.8 - 7.0 μm) or ultradispersed crystallites (290 - 480 nm) of hydrogen forms of nanoporous natural zeolites H-CL, H-MOR, H-HEU-M, H-PHI and under irradiation of the reaction mixture with ultrasound (US, 37 kHz, 330 W, 2 h) or microwaves (MW, 2450 MHz, 300 W, 2 h). Ultradispersed crystallites of zeolite catalysts were prepared from hydrogen forms of parent natural zeolites by their treatment with US or MW. In the esterification, the synergism of the actions of catalysts and MW or US was revealed;wherein on the ultradispersed best catalysts H-HEU-M and H-MOR conversion of 4-NBA and yield of ethyl 4-nitrobenzoate reached up to 70% and 67%, respectively. GC/MS, FTIR, NMR methods were used in the study.