ИСТИНА

The paper looks at recent research dealing with nanocalorimetry which is a modern method for analyzing various materials, allowing experiments to be carried out on samples of low mass (several nanograms) at high heating rates. This method involves the use of MEMs-sensors, the main part of which is a nitride-silicon membrane with low thermal conductivity and a thickness of less than 1 micron. Developed on the basis of the laboratory of engineering materials science of Lomonosov Moscow state University, unique device “Nanocalorimeter” has an open-type design that allows to combine thermophysical analysis with other methods of physical and chemical analysis to identify the mechanisms of complex phase transitions occurring during the heat treatment of materials, and a more detailed study of the functional nanostructured materials. It is shown that combining nanocalorimetry with micro-and nanofocus X-ray diffraction allowed to study complex phase transitions in poly(trimethylene terephthalate) (PTT) samples and propose a new model of melting-crystallization of semi-rigid polymers, different from the classical one. It should be mentioned, that using additional cooling accessories, the nanocalorimetry method was used to study mesophase formation at different cooling rates of isotactic polypropylene samples. Our future plans are to use the combination of nanocalorimetry with micro – and nanofocus X-ray diffraction and optical microscopy, in order to study the thermal behavior of crystalline monomers, which include azide and ethinyl groups, as well as triazine cycles. These materials are used to synthesize triazole-containing hyperbranched polymers (HPs), which, due to their good solubility and polarity, can be used in supramolecular chemistry in the development of optical materials, new electrolytes and ion-conducting elastomers. Given the sufficiently high heat of formation of triazole-containing HPs, high density and low sensitivity to mechanical stress, they can be especially useful when used as an additive with high energy capacity to improve the properties of polyurethane binders for rocket fuel. The proposed method will allow to decompose the observed processes into physical (phase transitions) and chemical (actually, the reaction occurring in different phases) and as a result exhaustively describe the kinetic laws and the conditions the synthesis of HPs based on monomers of different structures.