The following conclusions were drawn from an analysis of the data obtained: the use of methods of spatial separation of components increases the acceptable storage times for prepregs to The use of methods of laminar (LAC) and separate (SAC) application of components are examined here as methods that allow deliberately regulating the technological properties of the prepreg and the operating characteristics of the materials obtained. These methods are based on spatial separation of the functional groups of the epoxy resin and the functional groups of the curing agent.Use of the LAC and SAC methods potentiates the diffusion hindrances in curing, which allows regulating the strength characteristics of polymeric composite materials (PCM) and increasing the acceptable storage times of prepregs due to reduction of the mobility of the molecules of the curing agent.The traditional method of fabrication of prepregs is based on combining a filler with stoichiometric mixtures of resin and curing agent (mixed method) and subsequent processing of the prepreg by winding or direct molding. A drawback of this method is the nonuniform impregnation of the filler in pouring the binder on the lap, i.e., the difficulty of attaining uniform distribution of the binder in the filler due to the large difference in the specific volumes of the fibre filler and binder. To prevent unimpregnated areas in the article, an excess of binder (50 wt. % concentration and higher) is added. The excess binder is pressed out of the mold during formation, which is not economical. Another drawback of the mixed method is the limited acceptable shelf life of prepregs containing an epoxy resin and a curing agent, for example, when cold curing agents of the polyethylenepolyamine (PEPA), triethylenetriamine (TETRA), and triethylenetetramine (TETA) type are used, it is no more than I h at room temperature.To eliminate these drawbacks, improve the strength properties, and make the fabricated material less expensive, the filler was impregnated with epoxy binder by the LAC or SAC methods. The resin and curing system was spatially separated by layers on one element of the filler with the LAC method and the resin and curing system were applied on different elements of the filler with the SAC method.In conditions of molding at high temperature and pressure and in conditions of heat treatment, the resin was cured on some fibres due to the excess of curing agent on the other fibres (SAC method), and both types of fibres must be mixed [ 1,2] or due to diffusion of molecules of the curing agent from the outer to the inner layer (LAC method) [3][4][5]. In using the LAC method, a protective polymer is additionally added to the curing system applied with the second layer on top of a layer of resin to regulate the mobility of the molecules of the curing agent in the conditions of storage [6].Viscose (VF, USSR Technical Specification TU 6-06-N58--79), Capron (Capron. TU 15897--79), and polyacrylonitrile fibres (Nitron, TU 13239--79) impregnated with ED-20 epoxy resin (GOST ...

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Different magnetic treatments were investigated and recommendations were made concerning industrial application of magnetic treatment of fibres freshly impregnated with binders in fabrication ofIn a homogeneous static magnetic field (SMF), orienting moment M acts on a particle of a substance [ 1 ] M= AX B2Vsin 2et, (1) 2~to where A Z is the difference in the magnetic susceptibility of the particle in directions parallel and perpendicular to its axis;/.t o is the magnetic constant; B is the magnetic induction; V is the volume of the particle; ot is the angle between the axis of the particle and the lines of force of the ME Moment M attempts to turn the particle so that the direction of its major axis will coincide with the direction of the magnetic lines of force.In an inhomogeneous magnetic field, force F arises:21a0 where Z is the permeability averaged over the volume.Force F attempts to orient the particle along the field gradient, i.e., perpendicular to the direction of the lines of force of the SMF [2].Magnetic moment M and force F can lead to the formation of anisotropic structures oriented along or across the direction of the lines of force of the SMF, respectively. These results of exposure to SMF are practically manifested if the viscosity of the material is sufficiently low. In polymer systems, this is possible in solutions and melts, and the molecules of the oligomer or segments of the macromolecules are the oriented particles. Such studies have primarily been conducted for unfilled polymers [ 1,2], and less frequently for filled systems [3]. The practical application of magnetic treatments in industry will make it possible to regulate the structure of polymer materials and improve their strength characteristics.The scientific novelty of the research described here is that the effect of SMF on the kinetics of curing, structure, and properties of SF-342A reinforced aniline--phenol--formaldehyde resin and some reinforced systems based on ED-20 epoxy resin was investigated for the first time.The technical novelty consists of the development of a simple and economically efficient industrial method for magnelic treatment of fibres freshly impregnated with binder instead of prolonged holding of the reinforcement in an excess of binder in a SMF [4].