SINGLE-STAGE AND SIMPLE FABRICATION OF PE FILMS DECORATED WITH HALLOYSITE NANOTUBES

ХІМІЧНІ ТЕХНОЛОГІЇ ТА ІНЖЕНЕРІЯ 93 DOI 10.20535/kpisn.2023.1-4.297046 UDC [678.742.2:549.623.9]:544.526.2+620.17](045) Kovinchuk Iryna1,2*, Sokolsky Georgii1, Lazzara Giuseppe2 Igor Sikorsky Kyiv Polytechnic Institute, Kyiv, Ukraine 2 University of Palermo, Palermo, Italy * Corresponding author: 1 SINGLE-STAGE AND SIMPLE FABRICATION OF POLYETHYLENE FILMS DECORATED WITH HALLOYSITE NANOTUBES Background. Environmental pollution with plastic waste is a global problem that requires searching for effective and safe ways to dispose or process secondary raw materials. The use of photocatalysts for polymer degradation is a modern approach. Combining photocatalysts with support material to improve stability, activity, and lifetime is an important area of research. Objective. The aim of the work was to develop a technique for applying nanomaterials to the surface of a polyethylene film by partially dissolving the upper layer of the polymer in a heated nanomaterial suspension, namely, aluminosilicate halloysite nanotubes in a solvent. Cyclohexane was used as a solvent. Methods.Thermogravimetric, optical, and dynamic mechanical analyses of synthesised samples were carried out, and their properties were compared with reference samples of pure polyethylene and treated without the addition of nano material. Results. A method of decorating PE film with halloysite nanotubes has been developed. The introduction of 2.83 % by mass under the condition of immersing the film in a suspension of HNTs in cyclohexane (3 % by mass) at a temperature of 50 °C for 120 seconds was achieved. The decrease of the contact angle of the sample to 77.11° indicates the inclusion of hydrophilic HNTs into the surface layer of PE. Optical analysis confirmed the uniform distribution of particles on the surface of the film. The synthesized samples show a decrease in mechanical properties such as elasticity and tensile strength due to the destructive effect of the solvent on the polymer. Conclusions. Different conditions of application of HNTs on the surface of PE films using cyclohexane were tested. A method allows to achieve the introduction of a maximum of 2.83 % by mass of HNT. This method confirmed the possibility of attaching nanomaterials, namely HNTs, to the surface of the film by partially dissolving the surface layer of the polymer. Unlike our previous study [3], where the solvent casting method was used to introduce the catalyst into the PE film, the above approach does not require complete dissolution of the polymer and heating of the material to high temperatures and can be applied to the processing of industrially produced PE films. The addition of functional materials can be useful for modifying the properties of films, in particular PE. Studying the peculiarities of adding a photocatalyst to a polymer film at ambient temperature and the technology of industrial production of a PE film capable of decomposition can be the next stage of research. Keywords: polymer, halloysite, nanomaterial, thermogravimetry, chemical technology Introduction The wide use of plastics, the difficulties of their recycling, and the long degradation time in ambi ent conditions give rise of environmental pollution on a planetary scale. Understanding this problem, the European Commission adopted the EU Plan, in which all plastic packaging will be recyclable by 2030 [1]. The biggest challenge is household waste, as a mixture of different types of contaminated plastics. One of the approaches used for processing household plastic is mechanical recycling. There are two types of mechanical recycling: Primary recy cling (processing exclusively uncontaminated plas tic of a single type into a product of equal quality) and Secondary recycling. A latter is often deman ding on materials since preliminary sorting by type and rejection of contaminated plastic or washing is Пропозиція для цитування цієї статті: І.В. Ковінчук, Г.В. Сокольський, Дж. Лаззара, “Одностадійне та просте декорування поліетиленових плівок галуазитними нанотрубками”, Наукові вісті КПІ, № 1–4, с. 93–98, 2023. doi: 10.20535/kpisn.2023.1-4.297046 Offer a citation for this article: Kovinchuk Iryna, Sokolsky Georgii, Lazzara Giuseppe, “Single-stage and simple fabrication of polyethylene films decorated with halloysite nanotubes”, KPI Science News, no. 1–4, pp. 93–98, 2023. doi: 10.20535/kpisn.2023.1-4.297046 © The Autor(s). The article is distributed under the terms of the license CC BY 4.0 94 2023 / 1–4 KPI Science News necessary. Thus, recycled material costs are often higher than pristine plastic, and the quality of the processed material decreases with each cycle. As an alternative, thermo-chemical recycling – is less demanding and often acceptable for heterogeneous raw materials. The main idea is to split the polymer into individual monomers to produce a high-quali ty secondary product. Quaternary recycling is used for highly contaminated packaging, namely, waste incineration for energy recovery. The most environ mentally friendly way for waste utilization is bio logical. Plastics can be degraded with the help of bacteria, fungi and enzymes. The disadvantage of biorecycling is its extremely long duration. Using landfills for waste disposal is one of the common methods, but it leads to soil and water contamina tion and occupies large areas. Solid phase photocatalysis is a promising re search topic for the removal of pollutants from the environment. Some commonly used photocatalysts for acceleration of degradation are TiO2, ZnO, ZrO2, SnO2, CoO, In2O3, ZrO2, Cu2O NiO etc. The introduction of 0.1 % of TiO2 in LDPE film leads to enhanced degradation up to 18 % mass loss after UV exposure during 300 h [2]. This work is focused on the degradation of PE packaging through photocat alytic processes where oxides of Ti/Mn display the most promising activity [3]. The mechanical mixture of TiO2 and MnO2 in a ratio of 1:1 added to the HDPE film in an amount of 1 % led to an increase in the rate of degradation of the polymer. After 90 h of UV irradiation composite film lost 21.2 % of the mass, while the pure polymer lost only 0.5 %. The nature of its properties explained the choice of man ganese dioxide. The choice of manganese dioxide was explained by its properties as a semiconductor widely used in catalysis, organic synthesis, and ener gy storage. Its distinctive feature is a narrow bandgap of around 1–3 eV, which allows it to be an active photocatalyst even in daylight [4]. To achieve higher efficiency of photocatalysts, the possibility of intro ducing such a support as halloysite nanotubes in a catalytic system should be studied. Halloysite (HNT) is a natural aluminosilicate of the kaolin group with Al : Si in the ratio 1:1, having the chemical formula Al2Si2O5(OH)4·nH2O, where n can vary from 0 to 4. The average size depends on the origin and ranges between 40 and 70 nm in diameter and 200–1500 nm in length [5, 6]. Dif ferent methods for introducing the nanopar (...truncated)