For the first time, data are presented on the main and generalised structural parameters of particulatefilled polymer composites (PFPCs) with hollow glass microspheres. The characteristics of Russian-industryproduced hollow glass microspheres of grade MS-VP-A9 are given, and generalised structural parameters for different PFPC groups, which determine their processing and service properties, and also the choice of an effective processing method, are calculated.To create polymer composites with a specified combination of processing and service properties, disperse powder fillers are used [1]. Light polymer composites with a high specific surface are obtained by using hollow microspheres, and such materials have been named spheroplastics [2][3][4]. Russian industry is producing hollow glass microspheres of grade MS-VP-A9 (TU 6-48-91-92). A small number of foreign companies are also producing hollow glass microspheres (HGMSs): Dupont and Ceno TechnologiesIn contrast to non-porous fillers, the properties of hollow fillers (microspheres) depend not only on their size and the nature of the material but also on the apparent density, the radius of the internal cavity, the thickness of the shell, and the type of porosity -open or closed.The present paper sets out data on the main characteristics of Russian-industry-produced hollow glass microspheres of grades MS-VP-A9(1l), MS-VP-A9(2), MS-VP-A9(4), and MS-VP-A9(5) (TU 6-48-91-92).When disperse fillers are introduced into polymer matrices, a particulate-filled polymer composite (PFPC) is formed. The model of the structure is described by the main and generalised parameters, which determine the processing and service properties of the polymer composite and have been examined in detail in earlier studies [5,6]. In calculation of the generalised structural parameters and compositions of PFPCs with hollow microspheres, it is necessary to use the volume ratios between the components or the true density of the hollow microspheres, as only in this case is the volume of the closed pores in the hollow particles taken into account.The true density (r sph ) of the HGMSs with known bulk density (r bulk ) and bulk particle packing density (the maximum proportion of filler j m ), which are determined by known procedures [4], can be calculated by means of the formula: ρ sph = ρ bulk /ϕ m and also by the formula of additivity: ρ sph = ϕ shell ρ shell + ϕ air ρ air = ϕ shell ρ shell + (1− ϕ shell )ρ air where r shell and r air are the true density of the shell material and air (r air = 1.29 kg/m 3 ) respectively, and j shell and j air are the volume fractions of the glass sphere and gas in a hollow microsphere.During processing under conditions of exposure to external pressures, for example during pressing, the
The results of investigating the rheological properties and processing characteristics of a system consisting of 60 wt% epoxy bisphenol A resin of type ED-20 and 40 wt% phosphazene-containing epoxy oligomer are given. The kinetic dependences of the shrinkage, residual stresses, and rheokinetics are obtained, and the gelation times, activation energy of viscous flow, and glass transition temperature are determined.
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