Fillers for polymer composite materials

ABSTRACT: Introduction. For the production of building products made of PVC, compositions are used that, along with the polymer, include additives: plasticizers, stabilizers, modifiers. This leads to a decrease in the chlorine content in the composition and increases the flammability of the productitself. Therefore, nanoparticles of various fillers are added into the compositions. Fillers inPVC compositions (more often inorganic, less often organic substances) are solid additives that differ from the polymer matrix in chemical composition and structure.In most cases, the main function of fillers is to reduce flammability and cut costs of the products obtained, in some cases they serve to impart or improve the following properties: reducing plasticizer absorption, changing in dielectric properties, increasing rigidity and hardness, reducing noise transmission, reducing toxicity of combustion products. Main part. Fillers are classified according to various criteria. According to the state of aggregation, they are divided into gaseous, liquid and solid. By their nature, they are divided into organic and inorganic; according to the source of receipt – reinforcing, strengthening, reinforcing, neutral; bythe size, particle shape and structure – into 4 main types: dispersed (powder); fibrous (fibers, threads, bundles, etc.); sheet (film) with a given structure (fabrics, paper, tapes, sheets, films, nets); volumetric (framework) with a continuous three-dimensional structure (bulk fabrics, felt, skeletal and porous frameworks). The most commonly used solid fillers, which are also called dispersed. The introduction of dispersed fillers into polymer composite materials (PCM) is more appropriate for creating mass-produced materials, more technologically advanced, with a low level of strength characteristics. Dispersed fillers are introduced into thermoplastics with high fracture energy to reduce their cost, increase stiffness and compressive strength, and improve their technological characteristics during processing. At the same time, their tensile strength and impact strength decrease due to reduction in the proportion of polymer in the filled composition. The introduction of solid and hard particles leads to an increase in the elastic modulus (E); and soft, elastic or gaseous fillers – to its decrease. According to the mechanism of action, dispersed fillers can be divided into inert ones, which do not affect the properties of the matrix and are introduced into its composition to reduce the cost of the composition, and active ones. Dispersed fillers are divided into mineral, organic and metal. The commonest of those are minerals. Conclusion. Thus, at present, there are a large number of substances and materials used as fillers and making it possible to obtain PCM with low shrinkage and shape stability of products, high mechanical properties and the necessary set of special properties. Due to fillers, PCM can compete with other materials such as glass, ceramics and even metal in most areas of human activity