Secondary Polyethylene Research Articles

Study of the Dispersion of Bitumens Modified with Secondary Polyethylene Terephthalate

Study of the Dispersion of Bitumens Modified with Secondary Polyethylene Terephthalate

Modification of Petroleum Bitumen with Secondary Polyethylene in the Presence of Vermiculite

This article presents studies on the modification of petroleum bitumen with polymer waste in the presence of vermiculite. An increase in temperature leads to an increase in the interaction of components, partial breakage of polyethylene and bitumen macromolecules, and the formation of radical-free valences. As a result, fragments of polyethylene and bitumen molecules react with each other, and the formation of qualitatively new structural formations occurs via the strong connection of polar and amorphous bitumen with nonpolar structurally viscous polyethylene. Domestically produced Kulantau vermiculite was used to ensure stable adhesion over a wide temperature range and increase the specific surface area, which acquired additional energy, resulting in an increase in the degree of adhesion to bitumen and increased durability of the binder with improved rheological characteristics. Because of the increased service life of road asphalt pavements, the use of the latter results in a considerable decrease in the cost of polymer-bitumen binders. Based on improved binder formulations, asphalt concrete exhibits excellent water resistance and strength at 50 °C (4.7 to 5.0 MPa). In summary, the modification of bitumen with polymer waste and vermiculite offers a promising avenue for improving the performance and longevity of asphalt pavements.

In vitro cell-transforming potential of secondary polyethylene terephthalate and polylactic acid nanoplastics

Continuous exposure to plastic pollutants may have serious consequences on human health. However, most toxicity assessments focus on non-environmentally relevant particles and rarely investigate long-term effects such as cancer induction. The present study assessed the carcinogenic potential of two secondary nanoplastics: polyethylene terephthalate (PET) particles generated from plastic bottles, and a biodegradable polylactic acid material, as respective examples of environmentally existing particles and new bioplastics. Pristine polystyrene nanoplastics were also included for comparison. A broad concentration range (6.25–200 μg/mL) of each nanoplastic was tested in both the initiation and promotion conditions of the regulatory assessment-accepted in vitro Bhas 42 cell transformation assay. Parallel cultures allowed confirmation of the efficient cellular internalisation of the three nanoplastics. Cell growth was enhanced by polystyrene in the initiation assay, and by PET in both conditions. Moreover, the number of transformed foci was significantly increased only by the highest PET concentration in the promotion assay, which also showed dose-dependency, indicating that nano PET can act as a non-genotoxic tumour promotor. Together, these findings support the carcinogenic risk assessment of nanoplastics and raise concerns regarding whether real-life co-exposure of PET nanoplastics and other environmental pollutants may result in synergistic transformation capacities.

Single and combined effects of secondary polyethylene microplastic on the growth of Pak choi and the soil microbiome composition

Single and combined effects of secondary polyethylene microplastic on the growth of Pak choi and the soil microbiome composition

Study of modified thermoplastic elastomers based on polyethylene chlorinated with thiokol rubbers

In this paper has been examined the mechanical properties of thermoelastoplastic polymer materials derived from polyethylene chlorinated with secondary polyethylene. In order to ensure the good performance of the thermoelastoplasts obtained in the external environment, attempts were made to increase their resistance to external influences by modifying them with 1% mass of polysulfide rubbers, and resistance to deformation was determined when studying the properties of the polymer material under UV light for 10 hours.

SOLID-PHASE POLYCONDENSATION OF POLYETHYLENE TEREPHTHALATE WITH TECHNOLOGIES OF ITS REACTIVE EXTRUSION

It has been experimentally confirmed that polyethylene terephthalate during its processing into products destruct without carrying out the process of solid-phase polycondensation. The conditions for both primary and secondary polyethylene terephthalate have been determined for carrying out the process of solid-phase polycondensation for its effective reaction extrusion with chain extenders. To confirm the effectiveness of the parameters of the solid-phase polycondensation process of polyethylene terephthalate, its reaction extrusion was carried out with commercially available chain extenders of the diepoxide class. The optimal content of chain extenders of the diepoxide class for changing the complex of physical, mechanical and rheological properties of polyethylene terephthalate modified by them was determined. It allows obtaining materials with an increased by 2.2 times characteristic viscosity.

TECHNOLOGY FOR OBTAINING SUPERCONCENTRATES (MASTERBATCH) BASED ON ALCOHOLYSIS PRODUCTS OF SECONDARY POLYETHYLENE TEREPHTHALATE

Regularities of alcoholysis of secondary polyethylene terephthalate (RPET) by diethylene glycol (DEG) have been studied. It is shown that with an increase in the amount of diethylene glycol taken for alcoholysis from 0.1 mol to 0.4 mol per 1 mol of the elementary unit of HPET, a decrease in molecular weight from 1480 to 707 and the associated melting point from 215 to 145 °C are observed, and also intrinsic viscosity from 0.075 to 0.05 dl/g. The physicochemical properties of the products of alcoholysis of SPET (PAPET) have been determined. It has been revealed that PAPET is slightly colored and this is an undesirable factor affecting the individuality of the color of masterbatches based on them. Washing out with PAPET leads to some increase in the molecular weight values and related other indicators of the final oligomers. The structure of PAPET has been studied by infrared spectroscopy and differential scanning calorimetry. It has been revealed that PAPET synthesized at a molar ratio of SPET : DEG of 1:0.4, in which the dropping point according to Ubellode is 155 °C, is most suitable for obtaining superconcentrates. On the basis of PAPET obtained under these conditions, formulations of black and white masterbatches for polyethylene terephthalate fibers have been developed. To ensure uniform dispersion of white (TiO2) and black (K-354 carbon black) pigments, polyethylene wax was added to the superconcentrates. Masterbatches have been obtained by dry method in a twin screw compounder equipped with a double strand head and a granulator. The technological properties of the developed black and white superconcentrates have been determined, which turned out to be very close to those of the superconcentrates used in production. Conducted production tests of these masterbatches have showed that they are not inferior in terms of performance to similar industrial masterbatches used for dyeing threads.

Obtaining Oligoether Polyols from Secondary Polyethylene Terephthalate

Obtaining Oligoether Polyols from Secondary Polyethylene Terephthalate

Research of fire resistance and physical-mechanical properties of secondary polyethylene

This article provides information on a new type of filler used for secondary polyethylene and improving the fire resistance of secondary polyethylene. The article summarizes the physico-mechanical results of fillers, improves the properties of secondary PE, and creates the scientific basis for the production of composite materials with pre-planned properties.

Research of the petroleum road bitumen modification process with secondary polyethylene terephthalate

Modification of bitumen with polymers is an effective way to improve its properties. Despite the sufficiently widespread use of this method, currently there are practically no appropriate methods of this process calculation. Moreover, there are almost no the models to determine the size of formed polymer particles in modified bitumen of non-traditional polymer modifiers. The paper gives a mathematical description of the secondary polyethylene terephthalate particles formation in bitumen during the process of its modification. In terms of the stochastic approach, we obtained the analytical expressions for the differential distribution function of polymer particles in size, as well as the average size, surface, and volume. According to the research, increasing the rotation speed of the stirring mechanism leads to a decrease of the average particle size of the polymer. We use free software wxMaxima to perform the calculations.

ДОСЛІДЖЕННЯ БЕЗПЕЧНОСТІ ВИКОРИСТАННЯ ПЕТ ПЛЯШОК ІЗ ВТОРИННОЇ СИРОВИНИ ДЛЯ ПАКУВАННЯ ХАРЧОВИХ ПРОДУКТІВ

In the food industry, various materials are used for packaging, including polymeric ones. Containers made from them have a number of advantages and conveniences both during transportation and in the process of storing packaged products, but they create significant risks of environmental pollution. It is disposable and needs to be disposed of or recycled after use.Packaging food products in containers made from secondary raw materials allows solving a number of environmental problems and reducing dependence on disposable containers. The introduction of innovative technologies using polymer waste of polyethylene terephthalate as a raw material for manufacturing, for example, bottles, also has economic feasibility.Polymer packaging is a potential source of pollution, harmful substances can migrate from it into food products, and therefore research is needed on the safety of using polymer materials made from secondary raw materials for packaging food products with regard to the migration of toxic components from them. Milk, alcoholic and low-alcohol products, oil, drinking water, vinegar, etc. are packed in polyethylene terephthalate bottles.The analysis of research and publications showed that special attention is paid to the safety of the use of secondary polymer containers in the food industry. To determine its compliance with food safety requirements, organoleptic and sanitary-chemical studies are performed, the level of migration of chemicals into the studied environment is monitored. The possibility of safe use of bottles made of secondary polyethylene terephthalate for packaging water and vegetable oil was investigated. But research on the migration of toxic components from bottles to other food environments is needed.The purpose of the article is to study the migration of toxic substances from bottles made from secondary raw materials into drinking pasteurized cow's milk, water-alcohol solutions, aqueous solutions of acetic and lactic acid of various concentrations.The article presents the results of a study of the safety of using bottles made entirely of secondary polyethylene tereph-thalate for packaging milk with a 2.5% fat content, alcohol-containing products with an alcohol content of 5% and 40%, as well as aqueous solutions of acetic and lactic acid of various concentrations. The determined indicators of migration of acet-aldehyde, acetone, butanol, isopropanol, methanol, ethylbenzene, dimethyl terephthalate and other toxic components into the studied environment comply with the established hygienic standards and do not exceed the permissible amount of migration. Bottles made entirely from recycled materials meet the requirements for containers. which is in contact with food products, and can be recommended for packaging the studied types of products

Properties of Epoxy Compositions Cured by Aminolytic Splitting Products of a Secondary Polyethylene Terephthalate and Polycarbonate

Properties of Epoxy Compositions Cured by Aminolytic Splitting Products of a Secondary Polyethylene Terephthalate and Polycarbonate

MODIFICATION OF BITUMEN WITH RECYCLED PLASTICS FROM WASTE MATERIALS

It is proposed to use plastic waste as bitumen modifiers with a special emphasis on recycled plastics. The potential use for improving the characteristics of bitumen and durability of roads is being considered. For the preparation of modified bitumen, it was used the BND 100/130 bitumen produced by LLP "JV CASPI BITUMEN" (Kazakhstan). Polymer household waste based on plastic bottles was used as objects of the research. Polymer waste was obtained by mechanical recycling. The main physical and mechanical characteristics of the modified bitumen were determined after routine tests, penetration and plasticity, softening temperature, Fraas brittleness temperature and microscopic analysis. The morphology of the modified bitumen was studied using scanning electron microscopy. An original formulation of the polymer-bitumen binder with improved performance characteristics compared to petroleum bitumen has been developed. The introduction of used polymer waste as a modifier does not require the installation of an additional homogenizer (colloidal mill), and there is no need to introduce a plasticizer to achieve the desired uniformity of the system and required by the Kazakhstan standard PMB 40 and PMB 90. Thanks to the use of this technological solution, it is possible to level the problem of disposal of household polymer waste with the polymer-bitumen binder production. This polymer modifier is characterized by low cost of its production. The advantage of the used polymer additive is the stage of polymer preparation - the process of joint chemical destruction of secondary polyethylene terephthalate in the presence of a highly elastic styrene-butadiene-styrene polymer to inhibit the delamination of polymer components in bitumen, due to which the problem of manufacturing high-quality homogenization of the product is solved.

Effect of the thickness of polyethylene insulation on flame spread over electrical wire with Cu-core under AC electric fields

Effect of the thickness of polyethylene (PE) insulator on flame spread over electrical wire with high thermal conductivity of Cu-core is experimentally investigated by varying the applied AC voltage (VAC) and frequency (fAC) in the ranges of 0 – 5 kV and 0 – 1000 Hz, respectively. Three outer wire diameters (Dout= 0.8, 1.1, and 1.5 mm) with the same core diameter (Dc= 0.5 mm) are used. For the baseline cases without applying electric field, the flame spread rate (FSR) decreases with an increase in the outer wire diameter. When AC electric fields are applied to the wires, flame shapes and FSRs are appreciably influenced. The FSR behaviors with AC electric fields are classified into four sub-regimes as the frequency increases: a decreasing FSR (Regime I) having a leaning flame toward the burnt wire side, an increasing FSR (Regime II) showing a splitting phenomenon from a single-peak flame to a double-peak one due to a dielectrophoresis phenomenon, a decreasing FSR again (Regime III) generating a globular molten PE near the flame front and forming a liquid film of molten PE via continuously migrating a part of molten PE toward the burnt wire side, and an increasing FSR again (Regime IV) showing vortex flames at the front and rear flame edges along with an electrospray of molten PE. These emphasize diverse effects of the dynamic behaviors of molten PE. The onset condition for the formation of the vortex structure is identified as fAC,cr∼VAC−2Dout, supporting that such phenomenon is generated by induced magnetic field. An intermittent rotation of secondary (main) molten PE around the wire is a new observation. The mechanism is suggested by a dielectrophoretic force. Excluding the cases experiencing an intermittent leaning flame toward the burnt wire side and an irregularly splitting flame, FSR under the influence of such complex dynamic-behaviors of molten PE could reasonably be characterized with the gradient of electric field intensity taken at the outer surface of PE insulator, the area ratio between insulator and core, and AC frequency in all the regimes.

Nanoplastic Generation from Secondary PE Microplastics: Microorganism-Induced Fragmentation

Concern regarding the pollution of the marine environment with plastics has been rising in recent years. Plastic waste residing in and interacting with the environment fragments into secondary particles in the micro- and nanoscale, whose negative impacts on the environment are even greater than those of the parent items. In this work, secondary high density polyethylene (HDPE) and low density polyethylene (LDPE) microplastics were produced by irradiation of virgin films following mechanical fragmentation. The fragments with size ranging from 250 μm to 2 mm were selected for subsequent microcosm experiments. Incubation for 120 days in seawater inoculated with two marine communities, Agios, acclimatized to utilizing plastics as a carbon source, and Souda, as was collected at the Souda bay (Crete, Greece), resulted in biofilm formation by polyethylene (PE) degraders. Monthly FTIR (Fourier-transform infrared spectroscopy) examination of the samples revealed changes in the chemical structure of the surface of the polymers. Dynamic light scattering (DLS) was employed and nano- and microparticles with sizes in the range between 56 nm and 4.5 μm were detected in the seawater of inoculated microcosms. It was thus demonstrated that weathered plastics particles can biodeteriorate and biofragment as a result of biofilm attachment, resulting in the production of nanoplastics due to microbial activity.

Вплив графіту на фізико-механічні характеристики та трибологічні властивості вторинного поліетилену

The purpose of the work is to study the influence of graphite on the physical and mechanical characteristics and tribological properties of secondary polyethylene. For this, a study of the physical and mechanical characteristics and tribological properties of the original secondary polyethylene on PCM based on it was carried out. The influence of the concentration of graphite in secondary polyethylene on the value of strength stress and relative elongation under tension at the maximum load and destruction of the samples was determined. It was established that the optimal concentration of graphite should not exceed 2 wt. %. An increase in the volume of the filler in the matrix leads to a significant decrease in the physical and mechanical characteristics of the obtained materials. It was established that the introduction of graphite into the structure of secondary polyethylene, regardless of its volume, leads to an increase in the microhardness of the obtained PCM. It was found that the temperature in the vicinity of friction, under the condition of friction without lubrication on steel 45 and the selected modes, did not exceed 69 ºС. An increase in linear speed above 0.5 m/s or pressure above 1 MPa leads to an increase in the temperature in the friction zone to 72...73 ºС, which is critical for polyethylene and leads to catastrophic wear of the samples. It was established that under the selected modes of friction, linear speed of sliding and pressure do not have a significant effect on the amount of wear and tear. The resulting polymer composite provides performance under the condition that the pressure does not exceed 1 MPa, and the linear speed is up to 0.5 m/s. For use in mechanisms and machines that work in friction conditions according to the criterion PV ≤ 0.5 MPa • m/s, it is possible to recommend the introduction of 2% by mass. graphite into the structure of secondary polyethylene. The introduction of graphite in the amount of up to 2% by mass. will allow to stabilize and moderately increase the strength characteristics of the obtained material, in comparison with unfilled polyethylene.

STUDY OF VARIOUS QUALITY CHARACTERISTICS OF POLYESTER FIBERS OBTAINED ON THE BASIS OF PRIMARY AND SECONDARY POLYETHYLENE TEREPHTHALATE

The aim of study is comprehensive determination of various quality characteristics of polyester fibers obtained on the basis of primary and secondary polyethylene terephthalate. The analysis of the raw material base of pre-oriented yarns (POY) threads has been carried out. The technological, physicomechanical properties, as well as the structure of the primary and secondary polyethylene terephthalate used in the production of the threads have been studied. The structure and properties of polyethylene terephthalate changed: the properties were worse, the structure were amorphous, the molecular weight decreased. The structure of recycled polyethylene terephthalate changed as a result of technological conversions in the production of POY fibers. This is due to a change in the thermophysical characteristics and structure of secondary polyethylene terephthalate under the influence of heat, moisture, and shear stresses. A comparative analysis of the physicomechanical properties of POY yarns obtained from primary and secondary polyethylene terephthalate has been carried out.

Joint influence of γ–irradiation and high temperature shear grinding on the IR spectra and surface–energy properties of polyethylene

The optical and surface-energy properties of polyethylene (PE) subjected to γ-irradiation and post-radiation, high temperature, shear grinding are presented. Comparison of the IR spectra of the initial and γ-irradiated PE shows that oxygen-containing groups and unsaturated bonds in the polymer macromolecules are formed and accumulate during their radiolysis in air, increasing with γ-irradiation dose. A redistribution of the products of radiation-chemical conversion on the surface of the polymer granules throughout the entire volume of the powder occurs after high-temperature shear milling to a powder as observed in the IR spectrum. Polar functional groups due to oxidation reactions are observed on the surface layer of the sample after post-radiation grinding. The initial polymer surface is weakly basic with an acidity parameter of −0.34. The value of the acidity parameter of the sample made of ground irradiated PE has an acidic surface with an acidity parameter of 0.65. γ irradiation of the secondary processing of PE waste with high-temperature shear grinding is a promising approach to obtain a secondary PE powder with specified parameters and different degrees of functionalization.

PROPERTIES OF SECONDARY POLYETHYLENE TEREPHTHALATE ALCOHOLYSIS PRODUCT.

PROPERTIES OF SECONDARY POLYETHYLENE TEREPHTHALATE ALCOHOLYSIS PRODUCT.

Investigation of the curing process of epoxy compositions by developed amine products based on household waste polyethylene terephthalate and polycarbonate

The objects of research are oligomers-hardeners obtained by aminolysis of secondary polyethylene terephthalate (PET) and polycarbonate (PC) household waste with an aliphatic amine (PEP).The epoxy-diane resin of the ED-20 brand was chosen as the binder cured by the obtained oligomers due to its availability, good properties, acceptable viscosity, and wide applicability. The study of some parameters of the curing of thermosetting resin by industrial and synthesized hardeners is carried out.The gelation times at elevated temperatures (in the range from 50 to 100°C) and the activation energies of epoxy compositions were determined, and the conversion of epoxy groups during curing at room temperature was studied. The analysis of the obtained data showed that the structural features of macromolecules caused by the introduction of PET and PC fragments have a negligible effect on the activation energy and affect only when cured at room temperature and increase the viability of the compositions, while the gelation time at elevated temperatures in the case of all the studied hardeners is almost the same.