Modification Of Oligomers And Reinforced Polymeric Composites By Carbon Nanotubes And Ultrasonic

The modern development of mankind is inextricably linked with the improvement of existing thermoplastics and thermosets, as well as the creation of new polymers, for example, nanomodified polymer composite materials, with new operational properties. The main problematic situations that occur in the development of these polymeric composite materials are obtaining of defect-free composite structures, practically without air inclusions, a uniform distribution of the reinforcing filler over the cross-section of the composite to ensure the completeness of the properties of the constituent components of the composite, and also to improve the properties of the components of which the composite consists. At the same time, a "cementing" role is assigned to the polymer matrix in the structure of the composite, which determines the direction of improvement of its structural, technological, and operational properties, for example, by modification. At present, the modification (physical as ultrasonic, chemical, and physicochemical) is the basic direction of improving the technological and operational characteristics of classical and nanomodified polymer composite materials. For nanomodified polymer composite materials, the need to deagglomerate and uniformly disperse nanomodifiers, for example, carbon nanotubes, in a liquid polymer matrix is added to the above problematic situations. This is due to the fact that these nanomodifiers due to their physical nature in the initial state are prone to aggregation, thereby impairing the properties of the final nanocomposite into which they are incorporated. Equally important is the design of technology and equipment for energy- and resource-saving, as well as highly productive molding of composites with predetermined properties.We reviewed that ultrasonic modification is widely used in many branches of industry and technology, for example, in chemical engineering for molding both thermosetting plastics and thermoplastics. The achievement of the necessary positive result from the cavitation effect in liquid polymeric media can be attained by varying the parameters of the cavitation treatment (frequency, amplitude, intensity, pressure, temperature, volume of the liquid medium being treated). The total height of the epoxy composition lift (the productivity of ultrasonic impregnation) in the impregnation of fibrous fillers with previously sonificated epoxy composition increases by 2.5-3 times. Ultrasonic treatment allows to increase the deformation-strength and adhesion characteristics of materials, to lower the level of residual stresses, to increase the durability, and, moreover, to significantly shorten the hardening time. Also low-frequency ultrasonic treatment is one of the most effective methods for distributing carbon nanotubes evenly in a polymer matrix. It was investigated that nanomodifiers lead to improved tensile strength and deformation, fatigue strength, electrical conductivity, and glass transition temperature. For example, we investigated that the strength of nanomodified polymer composite materials is lead to improved due to an insignificant (8%) increase of the elasticity modulus and a considerable (25%) increase of the fracture strength (8%) of the studied nanocomposites. It was showed that the physico-mechanical characteristics improved after nanomodification of an epoxy binders by an average of (20-30)%; the compression strength limit and heat resistance, by 70%. The destructive load of fiberglass increased by 2-3 times. Also the complexity of solving the problem of designing a technology and equipment for the production of classical reactoplastic polymer composite material is due to the need to investigate a set of issues, concerning with studying the interrelations between the structural, mechanical, and geometric parameters of products, on the one hand, and the technological factors of their production, on the other hand.