Utilization of polyethyleneterephthalate waste via creating of metal-filled composites.
Students Name: Dovha Yuliya
Qualification Level: magister
Speciality: Chemical Technologies of Polymeric and Composite Materials Processing
Institute: Institute of Chemistry and Chemical Technologies
Mode of Study: full
Academic Year: 2022-2023 н.р.
Language of Defence: ukrainian
Abstract: At this stage of development of industry and technology, three methods of dealing with synthetic polymer waste are used: 1) landfill, 2) incineration, 3) recycling. Landfilling and incineration of synthetic polymer waste leads to emissions of harmful, toxic and carcinogenic secondary pollutants into the environment. Secondary processing allows you to solve certain environmental problems, however, at this stage, this method remains inefficient, difficult to organize the collection and sorting of polymers and, as a result, the quality of the obtained secondary polymers is low. In this regard, the development of new methods of efficient utilization of secondary synthetic polymers attracts considerable attention, the result of which should be materials that can be easily integrated into existing technological lines. Polyethyleneterephthalate, as one of the most high-tonnage polymers, represents special attention from the point of view of developing an effective technology for its disposal or secondary use. Along with the mechanical processing of polyethyleneterephthalate waste, which is widely known, the methods of chemical disposal also attract attention. Among the various types of polymers, polyesters are the easiest to chemically process. This is due to the fact that ether bridges of polymer chains easily react with various nucleophilic reagents, giving a high yield of useful products. Chemical processing can be expressed in full depolymerization to monomers or partial depolymerization to oligomers. When small amounts of ethylene glycol and water are added to polyethyleneterephthalate, its partial depolymerization occurs and a mixture of oligomers is formed, which can be used again to produce polyethyleneterephthalate. Also, the obtained products can be used to obtain other valuable products [1]. To reduce the duration of the reaction, catalysts (Ca, Zn, Mn acetates, titanium alkoxides or tin-containing compounds) are used [2]. Depending on the chemical agents used, depolymerization processes can be divided into hydrolysis [1, 3], methanolysis [4, 5] and glycolysis [6, 7]. Today, glycolysis and methanolysis are of industrial importance. In this master’s thesis, it is proposed to metalize polyethyleneterephthalate waste to obtain metal-filled composites [8, 9]. This re-use of polyethyleneterephthalate waste will allow to expand the scope of their possible secondary application with the production of new composite materials. Object of the research: metallized household waste based on polyethyleneterephthalate. Subject of the research: study of the features of the formation of a copper layer on zinc-activated polyethyleneterephthalate household waste, study of the influence of the conditions of activation of polyethyleneterephthalate waste on the characteristics of the obtained polymer raw materials and their influence on the regularity of metallization. The purpose of the study: to establish the peculiarities of the recovery of copper ions on the zinc-activated surface of polyethyleneterephthalate waste in chemical metallization solutions, to investigate the peculiarities of the activation of polyethyleneterephthalate waste with powdered zinc, to investigate the structure of the copper coating obtained on polyethyleneterephthalate waste and to establish the effect of the metal content on the melt flow rate. Experimental studies obtained in the master’s qualification work are based on the use of modern research methods and a number of original developed methods. In the work, the technology of obtaining secondary raw materials based on polyethylene terephthalate waste was developed. Characteristics of substances used for research and methods of experimental research are given. A method of obtaining polymer waste in the form of disks of the same size is proposed, which is convenient during the study of kinetic regularities of the process of copper ion reduction in chemical metallization solutions. A study was carried out to establish the influence of the composition of the chemical copper plating solution on the features of the metallization of the activated polyethylene terephthalate surface. It was established that the use of a standard solution with a low concentration of sodium hydroxide is ineffective due to the low rate of reduction of copper ions and the low efficiency of using copper sulfate. The influence of technological parameters of the process of activation of polyethylene terephthalate waste in a ball mill on the kinetic patterns of copper ion recovery and the efficiency of using copper sulfate from chemical metallization solutions has been established. The structure of the copper layer obtained as a result of the reduction of copper ions on the zinc-activated polyethylene terephthalate surface in chemical reduction solutions was studied. The influence of the amount of copper contained on the surface of polyethylene terephthalate waste on the melt flow index was established. The master’s thesis consists of an introduction, 4 chapters, conclusions and a list of used literary sources containing 52 references. The material of the work is laid out on 81 pages of printed text and contains 15 tables and 23 figures. Key words: waste, polyethylene terephthalate, utilization, metallization, zinc, copper. List of used literature sources. 1. Yoshioka, T., Sato, T., & Okuwaki, A. (1994). Hydrolysis of waste PET by sulfuric acid at 150°C for a chemical recycling. Journal of Applied Polymer Science, 52(9), 1353-1355. https://doi.org/10.1002/app.1994.070520919. 2. Cardi, N., Po, R., Giannotta, G., Occhiello, E., Garbassi, F. and Messina, G. (1993), Chain extension of recycled poly(ethylene terephthalate) with 2,2?-Bis(2-oxazoline). J. Appl. Polym. Sci., 50: 1501-1509. https://doi.org/10.1002/app.1993.070500903. 3. Campanelli, J.R., Kamal, M.R. and Cooper, D.G. (1993), A kinetic study of the hydrolytic degradation of polyethylene terephthalate at high temperatures. J. Appl. Polym. Sci., 48: 443-451. https://doi.org/10.1002/app.1993.070480309. 4. Patent USA 3037050. 5. Patent USA 3403115.. 6. Vaidya, U.R. and Nadkarni, V.M. (1988), Polyester polyols for polyurethanes from pet waste: Kinetics of polycondensation. J. Appl. Polym. Sci., 35: 775-785. https://doi.org/10.1002/app.1988.070350317. 7. Baliga S., Wong W.T.(1989), Depolymerization of poly(ethylene terephthalate) recycled from post-consumer soft-drink bottles. J. Polym. Sci. Part A Polym. Chem., 27: 2071–2082. doi: 10.1002/pola.1989.080270625.. 8. Kucherenko А.N., Mankevych S.О., Kuznetsova М.Ya., Moravskyi V.S. (2020), Peculiarities of metalization of pulled polyethylene. Chemistry, technology and application of substances, 3(2): 140-145. https://doi.org/10.23939/ctas2020.02.140 9. Moravskyi, V., Dziaman, I., Suberliak, S., Kuznetsova, M., Tsimbalista, T., & Dulebova, L. (2017), Research into kinetic patterns of chemical metallization of powder¬like polyvinylchloride. Eastern-European Journal of Enterprise Technologies, 4(12 (88): 50–57. https://doi.org/10.15587/1729-4061.2017.108462.