ExtEndEd AbstrAct:One of the most common polymers is polyvinylchloride (PVC), which is on the third place after polyethylene and polypropylene in the world in overall production. High demand for PVC is caused by the possibility of its modification and production of wide range of materials and articles with improved properties as well as by cost-advantageous price -performance ratio, availability of raw materials, saving natural resources. Along with many advantages PVC has a serious drawback: abnormally low stability. The observed thermal aging of PVC begins at 100 о C, especially intensively the polymer decomposes during processing in the range of 160-180 о C. Therefore, to obtain high-quality products based on PVC one needs effective stabilization of polymer, that provides high technology in the processing and long service life without deterioration of consumer properties.An effective way to improve the efficiency of stabilizer is to add available, well-known secondary stabilizers, which action mechanisms are different, namely dipentaerythritol (DPET) that acts as an acceptor of HCI, and dinonylphenol (phosphite NF), that inhibits thermal degradation of PVC interaction with unstable carbonrally groups.

The paper presents the results of studies of the infl uence of the new plasticizer DES M-2 on the physical, mechanical, technological and operational properties of plasticate PVC. The effi  ciency of using M-2 DES for PVC plasticization is shown. Practical recommendations are formulated that are necessary when compiling PVC compound materials and products using DES M-2.

A characteristic feature of the development of various areas of the industry is currently ongoing displacement of traditional metallic materials by plastics. Polyvinyl chloride (PVC) takes one of the leading positions. One of the reasons of extremely rapid growth of PVC production is the fact that there is not another polymer, which could be subjected to such modification varied as it is done with polyvinyl chloride.

Metal stearates are widely used in various industries: as a thickener, lubricants, auxiliary desiccant, emulsifier for cosmetics, chemical additives to synthetic rubbers and a stabilizing component in polyolefins (PE, PP), ABS plastic, polystyrene, polyamide and polyvinyl chloride ( PVC). The greatest interest in using the metal salt of stearic acid is stabilization of PVC. At present, technologies for the synthesis of divalent metal carboxylates have evolved in three directions: synthesis technology in solution, in the melt and in the solid phase. The latter was the most laborious at the end of the last century due to the lack of equipment that allowed the imposition of mechanical energy on the material in sufficient quantity to initiate chemical transformation. In the literature, experiments are carried out on planetary mills, attritors, rollers and Bridgman anvils. In devices of a similar design, the best conditions for the chemical process between the components of the reaction mixture are created. The chemical reaction proceeds as a result of the creation and subsequent relaxation of the stress field when applying a mechanical action to the reaction mixture. However, they did not give a high selectivity for the target product; therefore, the chemical industry of stabilizing additives focused on solution methods for producing metal carboxylates. The authors of the article have developed a new approach for the synthesis of calcium stearate in the solid phase on a modified screw apparatus. Screw machines, in turn, provide an increase in the number of contacts between reagents and, more significantly, the area of the contact interface. In addition, heat generation due to friction in the contact area can further intensify the process. The influence of the temperature range inside the material cylinder - the reactor, the screw rotation speed on the technical characteristics and the yield of calcium stearate was investigated. Mathematical processing of the results of the full factorial experiment was carried out. A comparison of the adequacy of the obtained linear equation and experimental data is carried out.

An investigation was made of the effect of glycerin monoesters obtained by a single-stage pollution-free method on the processing properties of PVC. Glycerin monoesters synthesised on the basis of oleic, stearic, and higher isomeric acids lower the polymer melt temperature and raise the melt flow, and also the dynamic and static heat stability of PVC composites.