104 A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture www. grnjournal.us AMERICAN Journal of Engineering, Mechanics and Architecture Volume 01, Issue 07, 2023 ISSN (E): 2993-2637 UDC 678.742.046 STUDY OF PHYSICO-CHEMICAL PROPERTIES OF SULPHUR, NITROGEN AND PHOSPHORUS-CONTAINING OLIGOMERS 1 Toshev M. E, 2 Normurodov B. A. 3 Turaev Kh. Kh, 4 Pardaeva N. Zh. 1 Doctoral student, Termiz State University, Termiz, Uzbekistan 2 Doctor of technical sciences, Termiz State University, Termiz, Uzbekistan 3 Doctor of Chemical Sciences, professor. Termiz State University, Termiz, Uzbekistan 4 Teacher, School No. 9 in Termez. Termiz, Uzbekistan E-mail: normurodov1974@internet.ru Abstract. In this paper the synthesis of oligomers containing sulfur, phosphorus and nitrogen were studied of optimum conditions. The obtained oligomers were used as polyethylene fillers, and the effect on the physicochemical properties of polyethylene was studied. Also, the thermal stability of polyethylene filled with fillers after the addition of fillers was analyzed using TGA and TDA analyses. According to the obtained results, it was found that these oligomers improved the thermal physical-chemical properties of polyethylene. Key words: phosphorus-containing oligomer, nitrogen-containing compounds, viscosity, oligomers. Introduction. The main modern world trend in the development of any type of products is the creation on its basis of a wide range of models, types, brands, modifications that ensure the effective development of a rapidly growing modern economy, expanding the scope of products that increase the volume of its output. This trend is fully typical for modern, especially thermoplastic polymer materials. The development of modern technology requires all new materials with predefined properties, but the creation and development of new polymers does not practically occur[1,2].. The main goal, which is pursued when filling polymers, is to reduce the cost of products based on them. In the vast majority of cases, the introduction of fillers leads to an increase in the brittleness of the resulting composite material and a catastrophic decrease in its frost-resistance, which is particularly pronounced at high volume fractions of the filler. At the same time, the maximum possible degree of filling for polymers processed from the melt is limited by the value of the viscosity of the melt and, as a rule, does not exceed 40%. Filling always leads to difficulties in the molding of articles, which is associated with an increase in the viscosity of the melt compared to the melt of the unfilled polymer [3,4]. In general, the complex of properties of filled polymers is determined by the combined effect of a number of factors, the most significant of which are: the nature of the thermoplastic and filler, the shape and size of the filler particles, the mutual arrangement of the filler particles and the change in their local density over the sample volume, and the filler concentration [4,5]. The nature of the thermoplastic and filler primarily determines their compatibility when molding the composite material. If the polymer and the filler are incompatible, the resulting product will have reduced mechanical characteristics, since applying the load will destroy the adhesive bond, 105 A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture www. grnjournal.us which results in the separation of the matrix from the filler particles. If the adhesion work achieved by the contact of the polymer and the filler is large, then the load applied to the composite material will be distributed more or less evenly without significant stress concentration at the polymer-filler interface. At high strength of polymer-filler adhesion bonding, it is possible to produce composites with relatively high mechanical characteristics [6,7]. Experimental part This work is devoted to the preparation of effective fillers based on sulfur, nitrogen and phosphorus-containing oligomers for polyethylene. Therefore, the modification of known polymers, the development of polymeric composite materials filled with functional additives, or blended compositions, is today one of the priority directions in the development of polymers and composites with predictable properties. The production of new synthesized highly additive additives for polymeric materials, which have high heat resistance and flame retardant efficiency, stabilization of polymers, ecologically safe and economical for today, is an urgent task[8,9]. Physicochemical properties were studied: density, melting point, solubility, IR spectroscopy, and DSC in sulfur, nitrogen, and phosphorus-containing oligomers. Physico-chemical characteristics of the synthesized high-grade oligomer DAF-6 (Ammophos with sulfur-containing organic compounds) are presented in Table 1 Table 1. Physico-chemical characteristics of a high-grade oligomer Indicators Highly complete oligomer DAF-6 Density, g / cm 3 GOST 15139-69 1.40 Mp oC 130 Ƞхв 0.070 Solubility dimethylformamide Appearance and color viscous substance of brown color On the NDA-6 IR spectrum in the regions of 2850-1470 cm -1 there are absorption bands confirming the presence of -CH2-groups and absorption bands in the 1650 cm -1 region, confirming the presence of the -COHH2 group in the free state. The IR spectrum contains absorption bands in the 3400 cm-1 region corresponding to the primary -COHH2 groups and absorption bands in the 3300-3440 cm -1 regions corresponding to the secondary -COHHR groups. The deformation oscillations of all active groups are manifested in the form of strong narrow bands between the usual bands of deformation vibrations -CH2-CO- in the region 1400- 1465 cm -1 . The absorption bands in the 800 and 1600 cm -1 regions confirm the presence of -NH2 groups. The presence of groups containing phosphorus P = O and P-O-C in the region of 1000- 1180 cm -1 is confirmed by a broad intensive band and sulfur-containing compounds in the regions 400-900 cm -1 , 1040-1060 cm -1 and 1100-900 cm -1 [10,11]. In addition, narrow low-intensity bands containing sulfur-containing compound bonds appear in IR spectroscopy in the regions 600-800 cm -1 and 1460 cm -1 . When considering IR spectra of NDA-6, intensive -CH2-N- groups with dimmer indices of 1400-1440 cm -1 and organic phosphates of 1180 cm -1 1150 cm -1 are seen. (Fig. 1). 106 A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture www. grnjournal.us Picture 1. IR spectrum of sulfur, nitrogen and phosphorus-containing oligomer of DAF-6 brand. Results and Discussion The influence of oligomers on the DSC process of a sulfur, nitrogen and phosphorus-containing oligomer of the DAF-6 brand was studied. The weight of the DAF-6 sample does not change to 207 ° C. A single endothermic peak (at 184.1 ° C) is observed on the DSC curve in the temperature range 20 -207 °C, which corresponds to the melting of the sample. Above the temperature of 207 °C, the sample begins to decompose in two stages - up to 265 ° C at a rate of 6% / min, and above 265 °C at a rate of 2.5%/ min, with a total weight loss of 73%. The decomposition reaction is endothermic, the total decomposition energy is -302.7 J / g. Fig.3. Figure.2. DSC sulfur, nitrogen and phosphorus-containing oligomer DAF-6 Conclusion. Thus, the characteristic properties of the sulfur, phosphorus and nitrogen containing oligomer were determined by IR spectroscopy and DSC, as a result of laboratory tests and it was proved that the oligomer can be used as high-grade additives for polymeric materials References 1. Kerber ML, Vinogradov VM, Golovkin GS, etc. Polymer composite materials: structure, properties, technology: training. allowance // SPb .: Profession, 2008. 560 pp. 2. Egorova OV, Artemenko SE, Kadykova Yu. A. Polyethylene compositions filled with dispersed basalt // Plastic masses, 2012. №9. Pp. 38 -39. 50 100 150 200 250 300 350 Temperature /°C -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 DSC /(mW/mg) 30 40 50 60 70 80 90 100 TG /% [1] 6.dsv TG DSC [1] [1] exo 107 A journal of the AMERICAN Journal of Engineering, Mechanics and Architecture www. grnjournal.us 3. Shostak TS, Budash Yu. A., Pakharenko VV, Stashkevich IA, Pakharenko VA Compositions based on PE filled with aluminosilicate // Plastics, 2011. №4. 39-43. 4. Nei Zo Lin., Averyanova MN, Osipchik VS, Kravchenko TP Structural and Mechanical Properties of Highly Filled Polyolefin Compositions. Uspekhi in Chemistry and Chemical Technology, 2014. T. XXVIII. №3 (152). P.55-57. 5. Usmani A. M.: Chemistry and technology of polysulfide sealants. Polymer-Plastics Technology and Engineering, -1982. –V.19, -pp.165–199. doi: 10.1080/03602558208067730 6. Normurodov B.A., Turaev Kh.Kh., Jalilov A.T., Nurkulov F.N., Rasulova S.M. Study of the physicochemical properties of the resulting polysulfide oligomer based on sodium tetrasulfide and ammonium phosphate // Universe: technical sciences, -2018. -No. 7(52), p. 34-37. 7. Kadirov D.M., Nefediev E.S., Kadirov M.K. Differential scanning calorimetry of thiokol composite //Structure and dynamics of molecular systems. - 2016. - S. 55-55. 8. Ostanov Yu.Yu., Beknazarov Kh.Kh. S., Jalilov A. T. Study of thermal stability of polyethylene stabilized by gossypol derivatives by DTA and TGA method //Plastic masses. – 2010. – No. 8. - S. 27-29. 9. Normurodov B.A., Tozhiev P.Zh., Turaev H.Kh., Jalilov A.T., Kiemov Sh.N., Pardaeva N.Zh. Highly filled thiokol oligomers for polyolefin compositions //Chemistry and chemical technology: achievements and prospects. - 2018. - S. 224.1-224.4. 10. Kochergin Yu.S., Grigorenko M.A., Grigorenko T.I., Loiko D.P. Properties of epoxy-thiokol mixtures subjected to a preliminary reaction of thioetherification // Questions of chemistry and chemical technology. – 2011. – no. 6. - P. 83. 11. Normurodov B.A. Synthesis of modified thiokol oligomers based on local raw materials and their applications: Cand. on the soy. uch. step. Doctor of Philosophy (PhD) in Technical Sciences, - Termez State University, 2019. - P.141