МОДИФИКАЦИЯ ЭПОКСИДНЫХ ПОЛИМЕРОВ НАНОДИСПЕРСНЫМ ОКСИДОМ АЛЮМИНИЯ

The aim of this work was to improve the physical, chemical and mechanical properties of epoxy composites with the use of nanosized aluminium oxide. The studies proved the possibility of directional control of the operational properties of epoxy composites by the use of small additions of nanosized aluminium oxide ensuring the creation of epoxy composites with high performance, satisfying the requirements of most industries. The rational content of aluminium oxide as a nanostructuring additive in an epoxy composition was selected (0,05 parts by weight). It ensures an increase in the complex of physico-mechanical properties (the breaking stress increases 3.3-fold, and the flexural modulus increases by 27%, the breaking stress in compression improves by 43%, the breaking stress and the tensile modulus of elasticity increases by 47-50%, the toughness increases 3-fold, and the hardness increases by 67%), while maintaining heat resistance. The introduction of nanosized aluminium oxide changes the parameters of the epoxy oligomer curing kinetics: the gelation duration increases from 45 to 75 minutes, and the duration of cure, from 53 to 100 minutes, while the maximum curing temperature is practically unchanged. Thus, the developed materials may be used for sealing electronic articles, for impregnating and filling components in aircraft engineering, shipbuilding and, automotive industry.Целью данной работы являлось повышение физико-химических и механических свойств эпоксидных композитов с применением в качестве структурирующей добавки нанодисперсного оксида алюминия. В результате проведенных исследований доказана возможность направленного регулирования эксплуатационных свойств эпоксидных композитов за счет использования малых добавок наноразмерного Al2O3, обеспечивающего создание эпоксидных композитов с высокими эксплуатационными свойствами, удовлетворяющими требованиям большинства отраслей промышленности. Выбрано рациональное содержание Al2O3 как наноструктурирующей добавки в составе эпоксидной композиции (0.05 масс. ч.), обеспечивающее повышение изученного комплекса физико-механических свойств: в 3.3 раза возрастает разрушающее напряжение и на 27% повышается модуль упругости при изгибе, на 43% повышается разрушающее напряжение при сжатии, на 47-50% возрастает разрушающее напряжение и модуль упругости при растяжении, в 3 раза возрастает ударная вязкость, а также на 67% возрастает твердость, при сохранении термостойкости. Установлено, что введение Al2O3 оказывает влияние на процессы структурообразования эпоксидной композиции при отверждении - увеличивается продолжительность гелеобразования с 45 до 75 мин и продолжительность отверждения с 53 до 100 мин, при этом максимальная температура отверждения не изменяется. Таким образом, разработанные материалы могут быть использованы для герметизации изделий электронной техники, для пропитки и заливки узлов в авиа-, судо- и автомобилестроении

Town Of Great Barrington, Massachusetts Annual Reports For The Fiscal Year 2016 July 1, 2015 to June 30, 2016

SABRE (Sodium-iodide with Active Background REjection) is a direct dark matter search experiment based on an array of radio-pure NaI(Tl) crystals surrounded by a liquid scintillator veto. Twin SABRE experiments in the Northern and Southern Hemispheres will differentiate a dark matter signal from seasonal and local effects. The experiment is currently in a Proof-of-Principle (PoP) phase, whose goal is to demonstrate that the background rate is low enough to carry out an independent search for a dark matter signal, with sufficient sensitivity to confirm or refute the DAMA result during the following full-scale experimental phase. The impact of background radiation from the detector materials and the experimental site needs to be carefully investigated, including both intrinsic and cosmogenically activated radioactivity. Based on the best knowledge of the most relevant sources of background, we have performed a detailed Monte Carlo study evaluating the expected background in the dark matter search spectral region. The simulation model described in this paper guides the design of the full-scale experiment and will be fundamental for the interpretation of the measured background and hence for the extraction of a possible dark matter signal

Spoilage at the thermoforming of layered materials

Steady growth of plastics industry necessitates the disposal of waste products from them. More and more manufacturers seek to include recycled materials and their technological waste in polimers compositions. Blending polymeric materials commonly used in the preparation of thermoformed articles from sheets of thermoplastics. Thermoforming process is cost effective, as it requires a significant investment in tooling in the manufacture of small batches of parts. In this study we investigated species discard practical use products, namely bath made by a combination of methods of thermoforming and contact molding coextruded sheets of ABS plastic with polymethylmethacrylate. Results of the study showed the veracity of the submitted samples assumption that as a raw material in the manufacture of sheets usedrecycled materials, which led to marriage in the finished product