667.64:678.026 V. A. Pakharenko, and V. V. EfanovaThe advantage of basalt fibres in comparison to glass fibres was demonstrated. The process parameters for production of basalt fibre are reported. The manufacturing processes in processing polypropylene composites with low combustibility and poly(ethylene terephthalate) composites filled with basalt fibres in lines based on a cascade screw-disk extruder are examined. Technology for obtaining polymer coatings using composites with basalt flakes and their properties are described.Glass and basalt fibres have become most common as mineral fibre fillers in production of polymer composite materials.The strength of basalt fibre is a function of its diameter. When the diameter increases from 7 to 13 μm, the strength of the fibre decreases from 2800 to 2000 MPa. Use of glass fibres of sodium-calcium-silicate composition is restricted to the temperature of 723-773 K, and alkali-free fibres are restricted to a temperature of 873-973 K. Basalt fibres are used at temperatures up to 1023-1073 K. At 973 K, the strength of basalt fibres only decreases by 50% with respect to the initial strength (glass fibres are destroyed at that temperature).Basalt fibres, like glass fibres, belong to the class of chemically stable fibres. At the same time, in contrast to glass fibres, higher resistance to aging and weatherproofing are characteristic of them. Basalt fibre withstands repeated treatment with live steam with no change in the properties.A 1-5% change in the humidity decreases the strength of glass fibres by 20-30% while the strength of basalt fibres is almost unchanged after 60 days in conditions of 100% relative humidity.If we compare glass fibre (GF), asbestos fibre (AF), and basalt fibre (BF), the advantage of BF can be noted: AF has limited application due to carcinogenicity, while GF changes the strength of fibreglass plastics during use and causes pulmonary silicosis.Basalt fibres are made from rocks. The approximate composition of BF is reported in Table 1. High thermal stability and chemical resistance, especially to bases, low water absorption, and good adhesion to polymers are characteristic of basalt fibres in comparison to glass fibres. The greatest advantage of basalt fibres is the high modulus of elasticity, equal to or greater than the modulus of elasticity of quartz and special high-modulus glass fibres. To create high-modulus glass fibres, special additives are incorporated in the glass melt; this changes the process conditions and significantly increases their cost, and basalt fibres have high elastic properties from the beginning.Basalt stock is melted at a temperature of 1450°C, the fibre is drawn through a platinum spinneret with pull rollers and it is then fed into a blowing chamber. The fibre is blown into a superfine fibre 3-7 μm in diameter and 50-70 cm long, and the density is 23-30 g/cm 3 . The temperature of use varies from -260 to +600°C and the moisture content does not exceed 2%. In order to not destroy the surface of BF and to increase adhesion betwe...

541.64 IR spectroscopy showed that dipole-dipole interactions of the hydrogen bond type with formation of stereocomplexes take place between macromolecules of the copolymer of ethylene with vinyl acetate (CEVA) and copoIyamide (CPA) The compatibility of polymers plays all important role in cross-linking processes in flow of melts of blends. There is an extensive literature on estimation of the degree of compatibility of polymers in different conditions of preparation of blends. The analysis of these studies forms the basis for re-examining the generally accepted concepts of the compatibility of polymers. Until recently, it was believed that polymers are usually thermodynamically incompatible and the following rule should apply in evaluating the compatibility of polymers: fike dissolves in like. However, it was found in [1, 2] that the number of compatible polymers is relatively low, and the best compatibility is attained not between polymers of like chemical structure, but between polymers whose macromolecules bear opposite origins, for example, the molecules of one component are proton (electron) donors and those of the other are acceptors. The compatibility improves due to dipole-dipole and iondipole interactions. Such relatively strong intennolecular interactions are the driving force of compatibility [ 1, 2].Blends of polymers with similar interaction of components are complex systems from the point of view of the rheological properties of melts and cross-linking characteristics. The degree of compatibility of polymers acts as the determining factor in realization of fibre formation of one polymer (fibre-forming) in the mass of another (matrix) in flow of a melt of a blend [3]. It was shown in [4] that in processing a melt of a blend of the copolymer of ethylene with vinyl acetate--copolyamide (CEVA CPA), ultrafine fibres (microfibres) of CEVA with a crimped surface due to induced deformation of the CEVA are formed. It was hypothesized that induced deformation of CEVA is due to the interaction between the macromolecules of CEVA and CPA on the phase boundary.We determined the type of interaction between macromolecules of CEVA and CPA by infrared (IR) spectroscopy. CEVA--CPA blends with a 20/80 and 80/20 ratio of components and the starting CEVA and CPA polymers were investigated. The characteristics of the polymers are reported in [5].The copolyarnide was evacuated at a temperature of 90~ to a concentration of volatiles of 0.05%. The components were blended in a LGP-25 disk extruder from Dneprpolimermash. A system of two disks --mobile and immobile, is the basic working organ of this extruder, and mixing takes place in the space between them as a result of shear and tensile stresses. Samples for recording the IR spectra in the form of a suspension in liquid petrolatum and a molded thin fihn were prepared from granules of the blend (or starting polymers). The IR spectra were recorded on a M-80 spectrometer in the range of wave numbers from 400 to 4000 cm -1. Recording the IR spectra of a suspension in ...

An analysis has been made of the effect of different additives on the properties of starch-based polymer composites. The authors describe the principal stages of the technology for producing such materials, which can be used for creating new ecologically safe biodegradable materials for the manufacture of films, packaging, and different products of short-time use. Their main trade names and manufacturers are given.

The rheological properties of melts of PP--CEVA blends include a decrease in the viscosity and an increase in the elasticity due to the specific features of fibre formation in flow of melts of the blends. The orientational draw ratio of composite PP--CEVA monofilaments increased in comparison toProduction of polypropylene (PP) fibres has recently increased at accelerated rates in the world due to the simplicity of the production technology and their valuable consumer properties: very low density, chemical resistance, sufficiently high physicomechanical characteristics, including high resistance to wear.Spinning of polymer blends from melts was a promising and widely used method of modifying synthetic fibres. Processing of polymer blends was a totally new way of fabricating ultrathin fibres (microfibres) [1,2]. We investigated the fibre-forming properties of melts of polypropylene---copolymer of ethylene with vinyl acetate (PP--CEVA blends). The characteristics of the polymers are reported in Table 1.Using CEVA as the matrix polymer (or as a third component) increases the homogeneity, kinetic stability of a polymer dispersion in a melt, and improves the compatibility capacity of the blends for processing into fibres [3,4]. We studied PP CEVA blends with a ratio of components of 100/0, 90/10, 80/20, 60/40, 20/80, and 0/100 wt. % and the composite monofilaments spun from these blends.Since fibre formation is primarily a function of the rheological properties of the melt, the viscosity l] and elasticity B of melts of the blends were measured. The viscous properties were deterlnined with a MV-2 constant-pressure capillary viscometer. The elasticity of the melt was indirectly judged by the degree of swelling of an extrudate of the blend annealed by the special method in [5].The fibres were not only spun in a shear field but to a significant degree in a longitudinal deformation field. The capacity of melts of the investigated blends for longitudinal deformation was evaluated by the value of the maximum possible spinneret drawing (Omax). For characterizing the structure of the disperse phase formed by the polymer in flow, the matrix polymer was extracted from an extrudate of the blend and the residues were analyzed m~der a microscope. PP was extracted with xylene, while CEVA was extracted with benzene. The composite monofilaments were spun on a laboratory spinning bench. The physicomechanical properties were evaluated for fibres drawn with the maximmn ratio.The viscosity of a melt of PP--CEVA blend as a ftmction of the ratio of its components is shown in Fig. 1. Note that the W-composition curves are positioned below the additive lines and have a minilnuln whose position is determined by the shear stress (z). Both in addition of CEVA to PP and in addition of PP to CEVA, the q of the blend decreases. This is a typical curve for the case where on flow of the blend, the polymer of the disperse phase forms liquid jets (microfibres after hardening) in the mass of the other polymer. The data obtained thus unambiguously show th...

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