Research of structure of oligomeric silsesquioxanes by x-ray scattering

• Main Authors: Андрій Олександрович Фоменко, Вікторія Олексіївна Овсянкіна, Аркадій Маркусович Шахновський, Анастасія Василівна Ніщименко
• Format: Article
• Language: English
• Published: Igor Sikorsky Kyiv Polytechnic Institute 2020-06-01
• Series: Вісник Національного технічного університету України «Київський політехнічний інститут імені Ігоря Сікорського»: Серія «Хімічна інженерія, екологія та ресурсозбереження»
• Subjects: полімерна матриця; силсесквіоксани; суміш; синтез; розсіяння променів; структура
• Online Access: http://chemengine.kpi.ua/article/view/207816

Creation of nanostructured organo-inorganic materials is one of the promising areas of today. The main problem that arise at using nanofillers is the difficulty of ensuring uniform distribution of the inorganic phase in the polymer matrix. Therefore, it is more rational to create nanoparticles that are able to covalently bind to the polymer matrix.This provides both uniform distribution of the inorganic phase and the combination of phases of different nature.  Polyhedral oligomeric silsesquioxanes (POSS) deserve attention in terms of their using as such nanostructuring agents. Today, octohedral oligomeric silsesquioxanes are the most widely used in the series. But their using for creating hybrid materials has difficulties such as high cost, complexity of their synthesis, one type of structuring in systems based on them.From the production point of view mixtures of oligosilsesquioxanes containing the POSS in the structure are more accessible. However, despite significant progress in the synthesis of nanostructured systems based on mixtures of oligosilsesquioxanes, studies of the properties and structure for such systems are virtually absent.The main purpose of the article is researching of the structure of the obtained systems based on oligomeric silsesquioxanes.     A mixture of oligomeric silsesquioxanes containing hydroxyl and tertiary amino groups (POSS-C) was synthesized. The structure of the obtained samples was studied by the methods of wide - and low - angle scattering of X - rays. It was found that PU,based on oligoethers and mixtures of POSS, form a completely amorphous structure. This occurs regardless of the type of polymer matrix and morphology.The presence of a mixture of POSS prevents the formation of crystals from the organic phase.It was established that the general amorphism of the fine structure of the studied PU is due to the ability of the mixture of oligosilvesquioxanes to reduce the density of the polymer matrix and the insignificant ability of the mixture of POSS to form crystals and crystallites. ong silicon-containing substances, POSS occupy intermediate position between siloxanes and silicates. On the other hand, they can be attributed to spherical siloxanes, because they consist of multifaceted structures, morphologically equivalent to a sphere. The presence of functional groups allows to get rid of a significant lack of siloxanes (do not form fibers and films) due to their low intermolecular interaction.Sisquioxanes can be processed at lower temperatures, both in pure form and in mixtures. Also they do not contain traces of metals. Systems based on POSS and polymers have synergistic properties. The ability to self-organize of systems based on POSS is very big advantage. This allows to obtain organo-inorganic materials with more perfect structural hierarchy. One of the areas of application of the synthesized crosslinked hybrid organo-inorganic systems is obtaining proton-conducting membranes of hydrogen engines.