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ISSN 2522-1841 (Online) AZERBAIJAN CHEMICAL JOURNAL № 3 2023 ISSN 0005-2531 (Print)
UDC 541.64:678.7
OBTAINING AND STUDYING THE PROPERTIES OF NANOCOMPOSITES BASED ON A MIXTURE OF HIGH AND LOW PRESSURE POLYETHYLENE WITH METAL-
CONTAINING NANOFILLERS
1 2 N.I.Kurbanova , G.G.Mammadova
institute of Polymeric Materials, Ministry of Education and Science of Azerbaijan Azerbaijan State Oil and Industry University
Received 28.10.2022 Accepted 13.02.2023
The effect of additives of nanofillers (NF) containing nanoparticles of copper (I) oxides stabilized by a polymer matrix of high-pressure polyethylene (PE) obtained by the mechano-chemical method on the structure and properties of metal-containing nanocomposites based on a mixture of high- and low-pressure polyethylene has been studied by differential thermal (DTA), X-ray phase (XRD) and scanning electron microscopy (SEM) analyses. It is shown that the introduction into the composition of 0.3 - 0.5 wt.% NF leads to an increase in the strength index from16.69 to 19.77 MPa and the amount of deformation at break of the composite by 1.7 times, which is apparently due to the synergistic effect related to the interfacial interaction of copper-containing nanoparticles in the LDPE matrix with the components of LDPE/HDPE composition , the mutual influence of which contributes to an increase in both the amount of deformation and the strength index. The study of the thermal properties of the samples has showed that the introduction of NF containing copper(I) oxide NPs into the composition of mixed polyethylene contributes to a significant increase in the decay temperature of the samples, and the activation energy of the decay of the thermo-oxidative destruction of the resulting nanocomposite increases from 232 to 255 kJ /mol. The results obtained indicate that small amounts of nanofillers (0.3-0.5wt. %), introduced into the polymer, obviously play the role of structurizers - artificial nuclei of crystallization, which contributes to the appearance of a fine-spherulite structure in the polymer, characterized by improved physico-mechanical and thermal properties of the resulting nanocomposite.
Keywords: high-pressure polyethylene, low-pressure polyethylene, copper oxide nanoparticles, strength, deformation, thermal properties, DTA, XRD and SEM analyses.
doi.org/10.32737/0005-2531-2023-2-53-60 Introduction
It is known that the modification method consisting in the creation of polymer-polymer compositions is widely used to improve the properties of industrial polymers [1].
In recent decades, the range of composite materials made from mixtures (alloys) of industrially important (base) polymers has expanded significantly. Most polymers are not compatible with each other. Such polymers include both high-pressure (LDPE) and low pressure (HDPE) polyethylenes. The main reason for incompatibility is their nonpolar nature [2]. To improve their compatibility, it is necessary to have functional groups in their composition or the introduction of compatibilizers or nano-fillers into the composition, which are an interfacial additive that contribute to improving both the compatibility of components and the operational properties of the materials obtained [3-9].
Fillers are the most important element of the structure of polymer nanocomposite materials. The functions of the filler in the latter are very diverse - from the formation of a complex of mechanical properties to giving the material a variety of specific properties. It determines the material strength, stiffness and deformabil-ity and the matrix ensures its solidity, stress transfer in the filler and resistance to various external forces. The properties of composites are largely determined, among other parameters, by the interface area and the intensity of intermolecular interaction between the matrix and filler materials. Since the particle size of the nanofiller is generally less than 100 nm, their higher specific surface area compared to fillers characterized by larger particles can significantly reduce the degree of the composite filling. Transition to the filler nano-dimensionality when optimizing the synthesis parameters helps not only to reduce its specific consumption, but
also to obtain materials with higher performance characteristics [10-13].
The use of dispersed nanofillers enables to control the structure and properties of materials due to the nucleating and orientation effects, the changes in the conformation of macromole-cules, their chemical binding to the surface of nanoparticles and the "healing" of structural defects [9, 10].
The development of studies on nanoscale and cluster metal-containing particles in polymer matrices was largely facilitated by the creation of metal-polymer composite materials with specific physical-mechanical and operational properties: increased thermal and electrical conductivity, high magnetic susceptibility, the ability to shield ionizing radiation, etc. [11, 12].
It is known that the use of d-valence metal nanoparticles (copper, zinc, cobalt, nickel, etc.) in polymers enables to obtain fundamentally new materials that are widely used in radio and optoelectronics as magnetic, electrically conductive and optical media [14-16].
The purpose of this work was to obtain and study the structure and properties of composites based on LDPE and HDPE with copper-containing nanofillers (NF) stabilized by a polymer matrix.
Experimental part
This work used the following:
- High-pressure polyethylene of 15803020 brand, p = 0.917-0.921, MFI 1.5-2.5 g10-1 min (T=1900C, load 2.16 kg);
- Low pressure polyethylene of HM0349PE brand, p = 0.949, MFI 8.3 g10-1 min (T=1900C, load 21.6 kg).
Copper-containing nanoparticles stabilized by a polymer matrix were used as nanofiller.
The nanofiller (NF) contains nanoparticles of copper (I) oxide which are stabilized by a mat-
rix of LDPE (high pressure polyethylene), obtained by a mechano-chemical method in a polymer melt without the use of a solvent. The content of nanoparticles is 5.0 wt. %, the size is 35±1.0 nm; the degree of crystallinity is 25-45% [17-19]. The ratio of the components of the composition (wt. %): LDPE/HDPE/NF=50/50/(0; 0.3; 0.5; 1.0)
Nanocomposite polymeric materials have been obtained by mixing sequentially HDPE and LDPE and then with a copper-containing nanofiller on laboratory rollers at a temperature of 1500C for 15 minutes. To carry out mechanical tests, the obtained mixtures were pressed in the form of plates 1 mm thick at 1900C and a pressure of 10 MPa for 10 minutes.
The physical-mechanical properties of the resulting compositions were determined with the use of the RMI-250 instrument. X-ray phase analysis (XRD) of the obtained compositions was carried out on a D2 Phaser device from Bruker, Germany.
Thermograms of the thermal stability of the samples were studied using a Perkin-Elmer STA6000 thermal analyzer. The tests were carried out in the air atmosphere in the dynamic mode when the sample was heated at 20 degmin-1 from 20 to 5000C.
SEM analysis of the resulting compositions was carried out using a Scanning Electron Microscope (SEM_EDXJSM-IT200LA, Joel, Japan).
Results and discussion
Nanocomposite polymeric materials based on LDPE and HDPE with copper-containing nanofillers have been obtained. The physico-mechanical, thermo-physical and thermal properties of the obtained nanocomposites have been studied.
Table 1 presents the physical and mechanical properties of the obtained composite materials.
Table 1. Physical and mechanical parameters of the obtained nanocomposites
Composition formulation (wt. %.), LDPE/HDPE/NF Breaking strength, MPa Specific elongation, % Vicat softening point, 0C
50/50/0 16.69 590 155
50/50/0.3 17.69 959 165
50/50/0.5 19.77 1000 175
50/50/1.0 17.78 690 160
As can be seen from the data in Table 1, the introduction of 0.3-0.5 wt.% NF into the composition leads to an increase in the strength index from 16.69 to 19.77 MPa. An increase in the concentration of NF more than 0.5 wt. % leads to a decrease in the strength of the composite (17.78 MPa), which is probably due to the aggregation of nanoparticles, leading to the formation of microdefects in the bulk of the polymer matrix. Introduction into the composition of 0.5 wt. % NF leads to an increase in the strain at break of the composite by 1.7 times, which is apparently due to the synergistic effect related to the interfacial interaction of copper-containing nanoparticles in the LDPE matrix with the components of the LDPE/HDPE composition, the mutual influence of which contributes to an increase in both the amount of deformation and the strength index. A study of the Vicat heat resistance of the obtained compositions showed that the introduction of a nanofiller into the mixture of LDPE/HDPE leads to an increase in the heat resistance index from 155 to 1750C.
Figures 1 and 2 show the XRD patterns of the initial LDPE/HDPE mixture and the mixture with a copper-containing nanofiller. The reflections corresponding to the initial mixture of LDPE/HDPE are shown: dhkl 4.46424;
4.11452; 3.72300; 2.48971 A (Figure 1) and reflections characteristic of copper (I) oxide na-noparticles: dhkl 3.02053; 2.46466; 2.13683; 1.74331; 1.51025; 1.28812 A (Figure 2), which corresponds to the dhkl series of copper (I) oxide according to the ASTM card file. [d-Spacings (20) - 01-071-3645 (Fixed Slit Intensity) - Cu Kal 1, 54056 A. Entry Date: 11/19/2008 Last Modification Date: 01/19/2011].
Figures 3 and 4 show thermograms of LDPE/HDPE and LDPE/HDPE/NF samples, which were used to calculate the thermal-oxi-dative properties of the obtained nanocomposites.
Since nanocomposite samples with 0.5 wt % of nanofiller containing copper (I) oxide nanoparticles, showed better physical and mechanical properties, the thermal stability of this sample was studied. The thermal stability of the studied samples of mixtures based on LDPE/HDPE, as well as mixtures containing NFs with copper (I) oxide NPs, was estimated from the mass loss and the activation energy (Ea) of the decomposition of thermal oxidative destruction, calculated by the method of double logarithm using the TGA curve according to the method [20].
The data obtained as a result of deriva-tographic studies are shown in Table 2.
JT>«* <Ca*M lalMnw! WL'1 MOW
Fig.1. X-ray diffraction pattern of LDPE/HDPE sample.
Fig.2. X-ray diffraction pattern of LDPE/HDPE/NF sample.
Fig. 3. Thermogram of a sample of LDPE/HDPE.
Fig. 4. Thermogram of a sample of LDPE / HDPE / NF Table 2. Thermal properties of the studied samples of LDPE/HDPE and LDPE/HDPE/NF
Composition formulation (wt. %) LDPE/HDPE/NF Ea , kJ/mol Mass loss,%
Temperature, 0C
425 450 470 480 490
50/50/0 232 0 1.0 2.5 4.0 8.0
50/50/0.5 255 0 1.0 2.0 3.0 6.0
As can be seen from the data of Table 2, the introduction of NF containing copper oxide NPs into the composition of mixed polyethyl-enes contributes to a significant increase in the decomposition temperature of the samples: up to 425 C, no weight loss is observed for both samples under study; at 4500C, a weight loss equal to 1%, at 4700C - 2.5%, and at 4800C -4.0%, at 4900C - 8.0% for the initial mixture, while for the composite containing NF with NPs of copper (I) oxide at 4500C a weight loss of 1% is observed; at 4700C, 2.0%; at 4800C, 3.0%; and at 490V, 6.0%. The activation energy (Ea) of the decomposition of the thermal ox-idative destruction of the obtained nanocompo-site increases from 232 to 255 kJ/mol.
Derivatographic studies have shown that the introduction of NF containing copper (I) oxide NPs into a mixture of polyolefins im-
proves the thermal and oxidative stability of the resulting nanocomposites.
Numerous experimental data on the mechanical, strength, relaxation, and other properties of polymer-polymer, polymer-filler mixtures are explained in terms of the concept of the presence of an interfacial layer [2].
The properties of polymer composites are significantly affected by the supramolecular structure of the polymer (the size of spherulites, the degree of crystallinity, the presence of various functional groups and various branches, etc.) and interfacial interaction at the interface.
It is known that at low concentrations (0.1-1.0 wt. %), the filler can serve as an artificial nucleus of structure formation [21, p.328].
The introduction of structure formers into the polymeric material leads to the formation of supramolecular structures with increased stability
and uniformity, which, ultimately, can provide isotropy of properties [21, p.80].
SEM analysis of the obtained composites was carried out (Figures 5, 6)
Figure 5 shows a micrograph of the LDPE/HDPE composite. As can be seen from the figure, the spherulites of each polymer do not mix with each other, forming a heterogeneous mixture.
Figure 6 shows a micrograph of the LDPE/HDPE/NF composite. As can be seen from this figure, the introduction of a nanofiller into the composition of the mixture contributes to the compatibility of the mixture components with the formation of a more finely spherulite homogeneous structure.
Fig.5. Micrograph of LDPE/HDPE composite.
Fig.6. Micrograph of LDPE/HDPE/NF composite. AZERBAIJAN CHEMICAL JOURNAL № 3 2023
The metal-containing nanoparticles used in the work, located at the boundary of the interfacial layer of the structural elements of LDPE and HDPE, contribute to the formation of heterogeneous nucleation centers in the composition melt, which, in the process of stepwise cooling of the nanocomposite, contribute to an increase in crystallization centers, leading in general to an improvement in the crystallization process and the formation of a relatively fine spherulitic structure.
SEM analysis of the obtained composites showed that small amounts of nanofiller (0.30.5 wt %) introduced into the polymer obviously play the role of structure formers - artificial crystallization nuclei, which contributes to the formation of a fine spherulite structure in the polymer, which is characterized by improved physical, mechanical and thermal properties of the resulting nanocomposite [22, 23].
Conclusions
The effect of a nanofiller containing copper (I) oxide nanoparticles stabilized by a polymer matrix of high-pressure polyethylene (PE) obtained by a mechanochemical method on the properties of mixtures of polyolefins based on LDPE and HDPE has been studied. XRD dif-fractograms confirm the presence of copper (I) oxide nanoparticles in the composition of a composite based on a polyethylene mixture.
The improvement of strength, deformation parameters, as well as thermo-oxidative stability of the resulting nanocomposite was revealed.
The work shows the prospects of use as an additive to a mixture of polyolefins based on LDPE/HDPE, nanofillers containing NPs of copper (I) oxide stabilized by a high-pressure polyethylene matrix obtained by a mechano-chemical method, which contributes to the creation of a fine-crystalline structure of the composition, and therefore its properties are improved, and thereby, the application areas of the resulting nanocomposite are expanded.
References
1. Ermakov S.N., Kravchenko T.P. Compatibility of polymers. Thermodynamic and chemical aspects. Plastic masses. 2012. No 4. P. 32-38
2. Pomogailo A.D. Molecular polymer-polymer compositions. Synthetic aspects. Successes of chemistry. 2002. V. 71. No 1. P. 5-38
3. Arzumanova N.B., Mustafayeva F.A., Kakhramanov N.T. Rheological Properties of Composites Based on Aluminum Hydroxide and Low- and High-Density Polyethylene Blends. Inorganic Materials: Applied Research.2020. V. 11. No 2. P. 429-434.
4. Kakhramanov N.T., Mustafayeva F.A., Arzumanova N. B., Gulyaev A.D. Crystallization Kinetics of Composite Materials Based on Polyethylene Mixture with High and Low Density. Inorganic Materials: Applied Research. 2020. V. 11. No 1. P. 127-131.
5. Novokshenov V.V., Musin I.N., Kimbelblat V.I. Dependence of the properties of PP/EPA mixtures on composition formulation and characteristics of polymers. Plastics. 2009. No 5. P.7-10
6. Kuchmenova L.Kh., Slonov A.L., Zhansitov A.A., Shelgaev V.N., Khashirova S.Yu., Mikitaev A.K. Study of the thermal properties of polymerpolymer compositions based on PP. Plastics. 2014. No 7-8. P.7-9
7. Sevastyanov D.V., Doriomedov M.S., Daskovsky M.I., Skripachev S.Yu. Self-reinforced polymer composites - classification, obtaining, mechanical properties and application (review). Electronic scientific journal "Proceedings of VIAM" 2017. No 4. P.104-118
8. Perestoronina Z.A., Ableev R.I., Baranets I.V., Kurlyand S.K. The effect of polymer additives on the enhancement of interfacial interaction in mixed thermoplastics. Rubber and resins. 2012. No 2. P. 13-16.
9. Zaikin A.E., Bobrov G.B. Oil-resistant thermoplastic elastomer based on a mixture of polypropylene and ethylene copolymer with vinyl acetate, vulcanized by hydrosilylation reaction. Bulletin of Kazan Technological University. 2013. V. 16. No 2. P. 105 - 108.
10. Mikhaylin Yu.A. Polymer nanocomposite materials. Polymer Materials. 2009. No 7. P. 10-13.
11. Tretyakov A.O. Polymer nanocomposites - materials of the XXI century. Equipment and tools for professionals. 2003. No 2 (37). P.18-20.
12. Foster L. Nanotechnology. Science, innovations and opportunities. M.: Technosphere, 2008. 352 p.
13. Pomogailo A.D., Rosenberg A.S., Uflyand I.E. Metal nanoparticles in polymers. M.: Chemistry, 2000. 672 p.
14. Cubin S.P., Yurkov G.Yu., Kosobudsky I.D. Na-nomaterials Based on metal-containing nanoparti-cles in polyethylene and other carbon-chain polymers. Intern. J. Materials and Product Technology. 2005. V. 23. No 1-2. P. 2-25.
15. Kurbanova N.I., Ragimova S.K., Alimirzoeva N. A., Ishenko N.Ya., Medyakov V.V. Composites based on isotactic polypropylene and high-pressure polyethylene with zinc-containing nanofillers. Inorganic Materials: Applied Research. 2022. V. 13. No 2. P. 485-488.
16. Kurbanova N. I., Guliyeva T. M., Ishenko N.Ya. Preparation and Properties of Metal-Containing Nano-composites Based on Isotactic Polypropylene and
Butadiene-Acrylonitrile Rubber. Russian Journal of Applied Chemistry. 2021. V. 94. No 1. P. 17-21.
17. Kurbanova N.I., Alimirzoeva N.A., Guseinova Z.N., Nurullayeva D. R. Ecological Method of Preparation of Metal-Containing Nanoparticles in Polyethylene Matrix. ITWCCST. 2017. Baku, Azerbaijan, 10-13 Sept. 2017. Book of Proceedings. P. 24-26
18. Kurbanova N.I., Kuliyev A.M., Alimirzoeva N.A., Aliyev A.T., Ishenko N.Ya., Nurullayeva D.R. Preparation of copper-containing nanoparticles in polyethylene matrix without use of solvents. Science and Technology of Polymers and Advanced Materials: Applied Research Methods. Editor(s): O.V. Mukbamam, T.N. Tatnshvili, M.J.M. Abadie to be published by Apple Academic Press, Inc. 2019. P.57-65.
19. Ragimova S.K. Obtaining the metal-containing nanoparticles in polyethylene matrix by mechano-chemical method and study of their properties. Azerb. Chem. J. 2020. No 2. P. 20-25.
20. Chemistry and physics of polymers workshop / edited by Doctor of Chemical Sciences, prof. V.F. Kurenkov. M.: Chemistry, 1990. P. 250-256.
21. Encyclopedia of polymers. M.: The Soviet. Encyclopedia, 1974. V. 2. P. 328.
22. Kuleznev V.N. Mixtures and alloys of polymers. Lecture notes. St. Petersburg: Scientific foundations and technologies, 2013. 216 p.
23. Kahramanli Yu.N. Incompatible polymer mixtures and composite materials based on them. Baku: Elm, 2013. 152
YUXARI УЭ A§AGI TOZYÎQLÎ POLÏETÎLEN QARI§IQLARI УЭ METALTORKIBLÏ NANODOLDURUCULARIN OSASINDA KOMPOZIT MATERlALLARININ ALINMASI УЭ TODQÎQÎ
N.i.Qurbanova, G.H.Mammadova
Mexaniki-kimyavi üsulla alinmiç polietilen matrisinda stabiïlaçdirilmiç mis (I) oksid nanohissaciklari (NH) saxlayan nanodolduruculann (ND) açagi tazyiqli polietilen(ATPE)va yüksak tazyiqli polietilen (YTPE)qançiqlari asasinda nanokompozitlarin xassalari termoqravimetrik (TQA), rengenfaz (RFA) va skanedici elektron mikroskopu(SEM) analiz metodlari ila tadqiq olunmuçdur. Gôstarilmiçdir ki, tarkiba 0,3-0,5 kütla% ND daxil edilmasi möhkamlik indeksinin 16.69-dan 19.77 MPa-a qadar va kompozitin qirilma deformasiyasinin 1.7 dafa artmasina sabab olur ki, bu da görünür, YTPE matrisindaki mis tarkibli nanohissaciklarin YTPE/ATPE tarkibinin komponentlari ila interfasial qarçiliqli alaqali sinergetik tasira göra, qarçiliqli tasiri ham deformasiya dayarinin, ham da möhkamlik indeksinin artmasina kömak edir. Tadqiq olunan nümunalarin istilik xassalarinin tadqiqi göstardi ki, qançiq polietilenlarin tarkibina mis(I) oksidi NH-lari olan ND-nin daxil edilmasi nümunalarin parçalanma temperaturunun va parçalanmanin aktivlaçma enerjisinin ahamiyyatli daracada artmasina kömak edir. Alinan nanokompozitin destruksiyada aktivlaçma enerjisi 232-dan 255 kJ/mol-a qadar artir. ôlda edilmiç naticalar göstarir ki, polimera daxil edilan kiçik miqdarda nanodoldurucu (0.3-0.5%), polimerda xirda sferulit strukturunun amala galmasina kömak edan süni kristallaçma nüvalari rolunu oynayir.
Açar sözlar: a§agi t3zyiqli polietilen; yüksak tazyiqli polietilen; mis(I) oksid nanohissaciklari; termiki xassalar; DTA, RFA va SEM analizlari.
ПОЛУЧЕНИЕ И ИССЛЕДОВАНИЕ СВОЙСТВ НАНОКОМПОЗИТОВ НА ОСНОВЕ СМЕСИ ПОЛИЭТИЛЕНОВ ВЫСОКОГО И НИЗКОГО ДАВЛЕНИЯ С MЕТАЛЛСОДЕРЖАЩИМИ
НАНОНАПОЛНИТЕЛЯМИ
Н.И.Курбанова, Г.Г.Мамедова
Исследовано влияние добавок нанонаполнителей (НН), содержащих наночастицы оксида меди (I), стабилизированные полимерной матрицей полиэтилена высокого давления (ПЭ), полученные механо-химическим методом, на особенности структуры и свойств металлсодержащих нанокомпозитов на основе смеси полиэтиленов высокого и низкого давления методами дифференциально-термического (ДТА) и рентгенофазового (РФА) и сканирующего электронного микроскопа (СЭМ) анализов. Показано, что введение в состав композиции 0.3-0.5 масс. % НН приводит к увеличению показателя прочности от 16.69 до 19.77 МПа и величины деформации при разрыве композита в 1.7 раза, что, по-видимому, обусловлено синергетическим эффектом, связанным с межфазным взаимодействием медьсодержащих наночастиц в матрице ПЭВД с компонентами композиции ПЭВД/ПЭНД, взаимное влияние которых способствует увеличению, как величины деформации, так и показателя прочности. Исследование термических свойств исследуемых образцов, показало, что введение НН, содержащего НЧ оксида меди(Г), в состав смесевых полиэтиленов способствует повышению температуры распада образцов, а энергия распада термоокислительной деструкции полученного нанокомпозита повышается от 232 до 255 кДж/моль. Полученные результаты свидетельствуют о том, что небольшие количества на-нонаполнителя (0.3-0.5 масс. %), вводимые в полимер, очевидно, играют роль структурообразователей - искусственных зародышей кристаллизации, что способствует возникновению в полимере мелкосферолитной структуры, характеризующейся улучшенными физико-механическими и термическими свойствами полученного нанокомпозита.
Ключевые слова: полиэтилен высокого давления; полиэтилен низкого давления; наночастицы оксида Medu(I); прочностные, деформационные, термические свойства; ТГА, РФА и СЭМ анализы.
