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It was established that, as a result of mixing low-density polyethylene and aluminosilicate, there is a change in the geometric parameters and in the size and shape distribution of the dispersed phase particles, which may be the consequence of their aggregation. For the composites investigated, there is an increase in the proportion of particles of smallest size and of lower anisotropy than in the initial filler. This may indicate the mechanical breakdown of the filler particles as a result of mixing with the polymer. The surface activity of the aluminosilicate particles during the crystallisation of polyethylene in the production of composite films was shown. The laws governing change in the physicomechanical characteristics of the filled composite films with increase in the filler concentration and their relationship with structural changes in the films were established.

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677.494.742The dynamic interfacial tension was determined in melts of fibre-forming polymer blends: was determined by the method of capillary decomposition of liquid polymer jets.The published values of the interfacial tension (Oab) for the same pairs of polymers differ significantly [1][2][3][4], which reflects the effect of the physicochemical characteristics of the polymers used and the characteristics of the methods of investigation used on this index. The present study was conducted to determine the ~rab of melts of fibre-forming polymer blends in the temperature ranges corresponding to the actual processing conditions.Fibre-forming polymers and polymers which have been suggested for use as modifying additives in fabrication of composite fibres were used:-isotactic polypropylene ( Of the different methods of measuring the interfacial tension [2] of polymer melts, we primarily selected methods based on an analysis of the dependent or sessile drop profile [3, 4]. These methods involve determination of the equilibrium profile of a drop of the polymer melt surrounded by a melt of another polymer and calculation of the equilibrium value of Oab. For polymer melts, the equilibrium profile is usually established in tens of minutes. At the same time, we know that the formation of the interfacial layer corresponding to the profile is accompanied by processes that cause a change in gab in time as a result of degradation and migration of low-molecular-weight homologs and surfactants to the phase boundary [5, 6]. The recorded "equilibrium" profile of the drop and values of Oab determined with it thus reflect the result of the processes listed above.The process of fabrication of fibrillar matrix fibres from polymer blends consists of dispersion of one component in the other and spinning of the polymer dispersion obtained, during which the disperse phase usually forms fibrils in a matrix of the basic component. A characteristic feature of these stages is the tension of the particles of the disperse phase, which leads at the limit to formation of liquid jets. According to the theory in [7, 8], the instability coefficient of a liquid cylinder suspended in another immiscible liquid is directly proportional to the value of trab between the cylinder and the liquid. In this respect, the physical meaning of Oab is that the interfacial tension is an effective destabilizing force which causes the liquid jet to decompose according to a capillary mechanism. Not the equilibrium value of Oab obtained for the layer established after a relatively long time, but some dynamic effective value of the interfacial tension realized during processing of the polymer blend is important for technological applications.*Determined according to GOST 11645.State Academy of Light Industry of Ukraine, Kiev.

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