Sleep disorder is one of the prominent manifestations of Angelman syndrome. The exact causes are unknown and methods of correction are difficult. The literature review is devoted to studies of the pathogenesis of sleep disorders in Angelman syndrome (the effects of gene function in 15q11–q13 deletion, findings in polysomnography, video-EEG sleep monitoring, laboratory data), on the basis of which recommendations for the correction of dyssomnia, including methods of behavioral therapy, are given.

The relevance of the study is conditioned by the fact that increased consumption of synthetic polymers leads to an increase in environmental pollution due to the long decomposition time of plastic waste. As a result, it is necessary to develop polymer composites based on a biodegradable polymer matrix, and to improve the performance properties of finished plastic products, it is necessary to purposefully select cheap and affordable inorganic fillers. Thus, the purpose of this study is to investigate the regularities in the generation of a spatially structured polymer matrix under UV irradiation of polylactide-based composites filled with aluminosilicate microspheres (ASM). The leading approach to the given problem is to melt polymer composites of various compositions and to determine the physical, mechanical, and thermophysical characteristics of the prototypes, including the supermolecular structure of the polymer matrix under the influence of ultraviolet irradiation. The study suggests that the filling of polylactide with ASM particles leads to an increase in the elastic modulus, a decrease in the strength at static rupture and resistance to dynamic destructive effects, as well as heat resistance. Small aluminosilicate microspheres, when added to polylactide, perform the function of nucleation and, even with a small content, increase the crystallinity degree by 3.7 percentage points. In the range of ASM content from 1 pph to 10 pph, the absolute value of the crystallinity degree practically does not depend on the filler concentration in the polymer composite. UV (ultraviolet) irradiation in the presence of air oxygen initiates the thermooxidative destruction of polylactide and leads to the establishment of a spatially structured polymer phase using the electrostatic intermolecular interaction of additionally formed oxygen-containing functional groups in macrochains, as well as partial intermolecular crosslinking during recombination of macroradicals. The establishment of spatial structures in the polymer matrix under UV irradiation determines an increase in the resistance of experimental samples to thermal effects. It is manifested in an increase in the bending temperature under load by 7-10 percentage points, a decrease in the crystallinity degree by 1.2-2.6 percentage points, a decrease in the fluidity of the meltage and also an increase in the glass transition and melting temperature. The materials of the study are of practical value for the development of biodegradable composites based on polylactide filled with inorganic components.

Thermoplastics in the recycling process are characterized by mechanical and thermo-oxidative degradation, which leads to deterioration of the operational properties of finished plastic products. A possible option for giving the secondary raw material optimal characteristics during processing may be the inclusion of aluminosilicate microspheres and modifiers that increase the fluidity of the melt. This paper presents the results of the study of rheological and physico-mechanical properties of polymer composites based on secondary polypropylene filled with aluminosilicate microspheres in the presence of stearic acid. It is shown that stearic acid increases the fluidity of the melt, improves technological performance during mechanical processing, including promotes uniform distribution of particles of aluminosilicate microspheres in the polymer volume. The optimal concentration of stearic acid is 0.5 % by weight, at which there is a maximum increase in the melt flow rate, a decrease in tensile strength of no more than 16 %, as well as an increase in resistance to dynamic impact without a significant change in the elastic modulus characterizing the stiffness of the material.

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