Processing Of Polymeric Materials Research Articles

Assessment of Solubility Behavior of a Copolymer in Supercritical CO2 and Organic Solvents: Neural Network Prediction and Statistical Analysis.

In the industrial sector, understanding the behavior of block copolymers in supercritical solvents is crucial. While qualitative agreement with polymer solubility curves has been evaluated using complex theoretical models in many cases, quantitative predictions remain challenging. This study aimed to create a rapid and accurate artificial neural network (ANN) model to predict the lower critical solubility and upper critical solubility space of an atypical block copolymer, poly(styrene-co-octafluoropentyl methacrylate) (PSOM), in different supercritical solvent systems over a wide range of temperatures (51.75-182.05 °C) and high pressure (3.28-200.86 MPa). The experimental data set used in this study included one copolymer, five supercritical solvents, one cosolvent, and one initiator. It consisted of seven unique copolymer-solvent combinations (252 cloud point pressures) used to predict the model quantitatively and qualitatively. To predict the PSOM-solvent interactions, the study considered two different input systems: a six-variable system, a five-variable system, and one target output. Initially, we used a three-layer feed-forward neural network to select the best learning algorithm (Levenberg-Marquardt) from 14 different algorithms, considering one sample PSOM-solvent system. Then, the network topology was optimized by varying hidden neuron numbers from 2 to 80 for all seven PSOM-solvent combination systems. The predicted cloud point pressures were in excellent agreement with the experimental cloud point pressures, confirming the model's accuracy. It is clear from the results of a minimum mean square error (≤1.90 × 10-27) and maximum linear regression R 2 (≥0.99) during training, validation, and testing of all the data sets. Further, the ANN model accuracy was tested by statistical analysis, confirming the model's ability to accurately capture the miscibility regions of polymers, enabling efficient processing of various polymer materials. This data-driven approach facilitates the prediction of coexistence curves for other polymers and complex macromolecular systems.

Processing of Layered Composite Products Manufactured on the Basis of Bioresin Reinforced with Flax Fabric Using Milling Technology.

In this work, a laminate based on bioresin and natural fibers was produced. Flax fabric was selected as the natural fiber. The biocomposite was subjected to strength tests. Stress-strain characteristics and strength indicators were determined. The workability of the laminate produced was also tested using milling technology. The tests were carried out using five carbide shank cutters for different purposes. The cutters with the geometry used in the processing of polymer materials and composites, general purpose cutters, and cutters with the geometry for aluminum and with different numbers of blades were analyzed. In order to obtain information on the workability of the prepared material, machining tests with different configurations of technological parameters were carried out. For each cutter, the effect of cutting speed and feed rate on the quality of the machined surface was tested. Due to the small thickness of the laminate, the machining was carried out in one pass, as a result of which the cutting depth in each case was constant. Changes in cutting speed and feed were evenly distributed over five levels. The quality of machining was assessed in two stages. The first stage included a visual assessment of the machined surface, involving a preliminary qualification of the machining parameters. The criterion was the amount of chips, frays, burrs, etc., remaining after machining that adhered to the surface. The next stage was the measurement of the geometric structure of the surface, during which the roughness parameters were analyzed using an optical microscope with a roughness analysis attachment. Quantitative analysis was performed for the best quality composite surfaces from each measurement series. The studies showed a dependence of the quality of machining on the technological parameters used. High tool speed, regardless of the type, especially at low feed, led to the sticking of chips, which had a very delicate form. In turn, low tool speed and high feed, due to the chip thickness, favored the formation of burrs. Machining with different types of tools showed that the process progresses better for tools with sharp blade geometry. Machining with a regular and polished cutter did not show any differences in the scope of the process progress.

Finite Element Analysis of the Structure and Working Principle of Solid-State Shear Milling (S3M) Equipment.

Solid-state shear milling (S3M) equipment is an evolution from traditional stone mills, enabling the processing of polymer materials and fillers through crushing, mixing, and mechanochemical reactions at ambient temperature. Due to the complex structure of the mill-pan, empirical data alone are insufficient to give a comprehensive understanding of the physicochemical interactions during the milling process. To provide an in-depth insight of the working effect and mechanism of S3M equipment, finite element method (FEM) analysis is employed to simulate the milling dynamics, which substantiates the correlation between numerical outcomes and experimental observations. A model simplification strategy is proposed to optimize calculation time without compromising accuracy. The findings in this work demonstrate the S-S bond breakage mechanism behind stress-induced devulcanization and suggest the structural optimizations for enhancing the devulcanization and pulverization efficiency of S3M equipment, thereby providing a theoretical foundation for its application in material processing.

Machine Learning in the Analysis of the Mechanical Shredding Process of Polymer Recyclates.

Artificial intelligence methods and techniques creatively support the processes of developing and improving methods for selecting shredders for the processing of polymer materials. This allows to optimize the fulfillment of selection criteria, which may include not only indicators related to shredding efficiency and recyclate quality but also energy consumption. The aim of this paper is to select methods of analysis based on artificial intelligence (AI) with independent rule extraction, i.e., data-based methods (machine learning-ML). This study took into account real data sets (feature matrix 1982 rows × 40 columns) describing the shredding process, including energy consumption used to optimize the parameters for the energy efficiency of the shredder. Each of the 1982 records in a .csv file (feature vector) has 40 numbers divided by commas. The data were divided into a learning set (70% of the data), a testing set (20% of the data), and a validation set (10% of the data). Cross-validation showed that the best model was LbfgsLogisticRegressionOva (0.9333). This promotes the development of the basis for an intelligent shredding methodology with a high level of innovation in the processing and recycling of polymer materials within the Industry 4.0 paradigm.

Numerical simulation for MHD Oldroyd-B fluid flow with melting and slip effect

This investigation reflects an examination of Oldroyd-B fluid flow over a permeable surface subjected to the effects of melting, slip effect, inclined magnetic field and chemical reactions. The governing equations are resolved using the bvp4c inbuilt MATLAB tool, the arithmetic computation for the momentum, thermal and concentration equations are executed. The results are exhibited graphically. Numerical outcomes are graphically depicted by aid of velocity, concentration, temperature profiles for several model variables. The achieved results exhibit a promising agreement with the previously established findings available in the open literature. The results obtained indicated that Deborah number β1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta_{1}$$\\end{document} reduces the momentum boundary layer thickness whereas Deborah number β2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta_{2}$$\\end{document} enhances the adjacent momentum boundary layer. Furthermore, temperature profile declined for melting parameter Me\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$Me$$\\end{document}. The application of this study transcends various engineering disciplines, offering practical solutions and optimization opportunities in polymer processing, coating technologies, cooling systems, materials processing, biomedical and environmental engineering.

High‐Resolution 3D Printing of Dual‐Curing Thiol‐Ene/Epoxy System for Fabrication of Microfluidic Devices for Bioassays

AbstractThe customized processing of polymer materials in the microscale by high‐resolution 3D printing provides an easy access to advanced applications in the fields of optics, microfluidics, tissue engineering, and life science. However, the 3D printing of enclosed structures in the scale of tens of microns such as closed microfluidic channels remains a challenge as channel structures often are clogged by residual cured resin. Dual‐curing systems based on off‐stoichiometric thiol‐ene and thiol‐ene/epoxy chemistry are well‐known for adhesive‐free bonding in the fabrication of cast or injection molded microfluidic devices. Herein, the first high‐resolution stereolithography 3D printing of a dual‐curing thiol‐ene/epoxy system in the microscale for the fabrication of customized microfluidic devices is presented. In the first curing step, by high‐resolution 3D printing open microfluidic structures are produced. Consecutively, the microchannels are sealed by adhesive‐free dry bonding upon thermal initiation, producing well‐controlled structures with channel sizes down to 80 µm. Before bonding, the intermediate material allows for tailored surface modification with biotin, which allows for consecutive immobilization of various biomolecules. A DNA‐bioassay with specific patterning is shown in the sealed chip. The presented work paves the way toward the fabrication of customized microfluidic devices for a large range of specific bioassays.

Efficient Pulsed Raman Laser with Wavelength above 2.1 μm Pumped by Noise‐Like Pulse

Herein, the efficiently high‐power pulsed Raman lasers with wavelength above 2.1 μm are experimentally demonstrated relying on the stimulated Raman scattering. A tailored high‐power noise‐like pulse (NLP) fiber laser system centered at ≈1953 nm with a maximum output power of ≈10.9 W is served as the pump source. By directly pumping a section of highly Ge‐doped silica fiber, the first pulsed Raman laser (centered at≈2139 nm) and the second pulsed Raman laser (centered at ≈2353 nm) with maximum output powers of ≈3.8 and ≈0.25 W are obtained, respectively, which represent the highest output powers of NLP at these wavelength regions, to the best of knowledge. Moreover, a high spectral purity of ≈94.3% of the first Raman laser is obtained, which indicates the significantly potential application of NLP in pulsed Raman laser. The midinfrared NLP fiber laser source will have potential applications in transparent polymer materials processing and midinfrared spectroscopy.

Polyolefin Pyrolysis in Multilayer Fluidized Beds: An Innovative Approach to Obtain Valuable Alternative Fuels

This paper presents the application of two versions of the multilayer fluidized bed made out of two materials with significantly different densities. The first type of fluidized bed was composed of raw cenospheres and quartz sand. The second type of fluidized bed was composed of cenospheres coated with iron oxides and quartz sand. A variable vertical density profiles in the prepared fluidized beds were confirmed, making them suitable for processing polymeric materials, specifically, polyolefins with a density below 1 g/cm3. The polyolefin pyrolysis process was investigated in both versions of the fluidized bed at temperatures of 520, 540, 560, and 590 °C. The products of the pyrolysis were monitored using high-resolution infrared spectroscopy (with a resolution of 1 cm−1). While the process is organized in these fluidized beds, the absence of the accumulation of solid residues is notable. The results show that the pyrolytic gaseous mixture is composed of numerous compounds, namely, unsaturated and saturated aliphatic hydrocarbons and benzene. The possibility of producing a gas rich in ethylene, propylene, and 1-butene during the pyrolysis was demonstrated. Additionally, during the pyrolysis of both polymers, the production of benzene was shown with yields, ranging from 5%wt. in the fluidized bed made out of raw cenospheres to 11 %wt. in the fluidized bed made out of cenospheres modified by iron oxides. Due to the complex nature of the resulting pyrolytic gas, it is suggested that we process the created gaseous mixtures entirely in a steam conversion process, making them a potential source of hydrogen.

Atmospheric Pressure Plasma Jet Exposure of Polylactic Acid Surfaces for Better Adhesion: Plasma Parameters towards Polymer Properties.

Polymers play a crucial role in multiple industries; however, surface modification is necessary for certain applications. Exposure to non-thermal plasma provides a viable and environmentally beneficial option. Fused deposition molding utilizes biodegradable polylactic acid, although it encounters constraints in biomedical applications as a result of inadequate mechanical characteristics. This study investigates the effects of atmospheric pressure plasma generated by a dielectric barrier discharge system using helium and/or argon on the modification of polylactic acid surfaces, changes in their wettability properties, and alterations in their chemical composition. The plasma source was ignited in either He or Ar and was tailored to fit the best operational conditions for polymer exposure. The results demonstrated the enhanced wettability of the polymer surface following plasma treatment (up to 40% in He and 20% in Ar), with a marginal variation observed among treatments utilizing different gases. The plasma treatments also caused changes in the surface topography, morphology, roughness, and hydrophilicity. Plasma exposure also resulted in observable modifications in the dielectric characteristics, phase transition, and structure. The experimental findings endorse the utilization of plasma technologies at normal air pressure for environmentally friendly processing of polymer materials, specifically for applications that necessitate enhanced adhesion and have carefully selected prerequisites.

EVALUATION OF THE THERMAL-OXIDATIVE STABILITY OF A HALOGEN-CONTAINING PLASTICIZER-FIRE RETARDANT

The importance of assessing the indicators of thermal-oxidative stability of plasticizers that are part of polymer compositions for ensuring high performance indicators during their processing and operation of finished products is noted. When using brominated organic compounds of the aromatic series, a short burning time of polymer compositions and a significant smoldering time have been established. The use of flame retardants containing a halogen in the aliphatic radical leads to a decrease in the smoldering time and an increase in the duration of combustion due to a decrease in the thermal stability of the material at the stage of decomposition. It is indicated that bromine-containing compounds give the best inhibition effect compared to chlorine-containing compounds due to a decrease in the carbon-bromine bond breaking energy compared to the carbon-chlorine bond energy. The decomposition parameters of the brominated plasticizer-fire retardant have been established. It is shown that the thermal decomposition of the brominated plasticizer occurs in two stages, corresponding to the elimination of bromine from the aliphatic radical in the temperature range 473 K – 573 K and the decomposition of phthalic acid esters in the range 603 K – 623 K. The beginning of intensive decomposition corresponds to 443 K. The maximum of the first stage of decomposition is at the point corresponding to 501 K, the second - 606-623 K. It was noted that the bromine-free plasticizer decomposes intensively, starting from 503 K and reaches the maximum decomposition rate at 611 K. The maximum loss of the bromine-free plasticizer was established at 27%, brominated - 50.9% of the mass of the sample. It has been confirmed that the presence of bromine atoms in the plasticizer adversely affects its thermal stability. The influence of the degree of halogenation of an unsaturated plasticizer on the nature of its thermal-oxidative degradation in the temperature range corresponding to the technological parameters of processing polymeric materials at elevated temperatures of 413-443 K has been studied. It is shown that an increase in the content of bromine in the plasticizer when performing technological operations for the processing of polymer compositions in the specified temperature range and the duration of exposure to elevated temperatures within one hour does not significantly affect the mass fraction of bromine in the plasticizer. A kinetic equation for the reaction of thermal decomposition of a bromine-containing plasticizer-flame retardant of the phthalate type, accompanied by the elimination of hydrogen bromide, is proposed. The activation parameters of the hydrogen bromide evolution reaction were determined for the temperature range of maximum decomposition of a brominated phthalate plasticizer with a bromine content in the range of 5% – 25%. It is shown that the activation energy of hydrogen bromide elimination depends on the bromine content in the plasticizer and decreases by 23% with an increase in the degree of bromination. It is shown that the temperature range of maximum decomposition of the brominated fire retardant plasticizer, corresponding to 473 K – 573 K, allows using it as a secondary plasticizer for polyvinyl chloride without reducing the thermal stability of the base.

Study of the modernized single-screw extruder body energy efficiency

The subject of the study is the energy efficiency of the polymer extrusion process in a single-screw extruder for the polymer materials processing.
 The purpose of the research is to improve the design of the feeding section of the single-screw extruder cylinder, which consists in placing thermal paste in the gap between the connecting cylindrical surfaces of the removable cylindrical sleeve and the channel of the feeding section cylinder, which reduces the thermal resistance of the section wall and improves heat transfer from the processed material to the cooling water, and therefore, it makes it possible to reduce its consumption.
 To check the energy efficiency of the proposed technical solution, thermal calculation of the basic and modernized structures of the feeding section cylinder was performed in the Steady Thermal model of the Ansys program. Polyvinyl chloride brand SorVyl G 2171/9005 11/01 was chosen as a recyclable polymer, alloy steel as the material of the feeding section elements, and thermal paste with a thermal conductivity of 4 W/(m·K) as a filler for the annular space between the cylinder and the sleeve.
 The analysis of the calculations showed that the use of thermal paste instead of air in the gap between the cylinder and the removable cylindrical sleeve reduces the thermal resistance of the cylinder wall by 9 %, while with the traditional method of assembling the extruder body, the temperature on the inner surface of the sleeve was 67.5 °C, and under the condition application of thermal paste – 61.5 °C. At the same time, the temperature field along the length of the feeding section of the cylinder is also equalized. In addition, it is worth noting that the type of thermal paste used has almost no effect on the thermal resistance of the section wall, so in the proposed design it is possible to use low-cost thermal paste (replacing the thermal paste with a thermal conductivity of 4 W/(m·K) with a more effective one with a thermal conductivity of 8.4 W/(m·K) reduced the temperature on the inner surface of the sleeve by only 1 K).
 The proposed improvement of the feeding section of the cylinder of a single-screw extruder can be applied not only in the polymer processing industry, but also in the food and processing industries in the construction of screw machines for various purposes.
 Reducing the thermal resistance of the cylinder section wall of the single-screw extruder ensures a reduction in the flow of cooling water circulating in the cylinder channel and equalizes the temperature field along the length of the feeding section of the cylinder, and therefore prevents premature melting of the polymer and ensures reliable generation of pressure in the working channel of the extruder.

Effect of uniaxial stretching on gas separation performance of polyimide membranes

Fine-tuning of the physical stacking structure for microporous polyimide (PI) membranes via the stretching processing is a practical way of achieving advanced membrane materials with improved aging resistance as well as high gas separation performance. Here, a fluorinated polyimide 6FDA:BPDA-TFDB(1:1:2) is used as a prototype and a series of stretched membranes X%-PI are fabricated by uniaxially stretching the membrane to different elongation ratio and then annealing. Based on birefringence and wide-angle X-ray diffraction measurements, it's found that regular orientation of polymer chains along the stretching direction and fine-tuning of d-spaces from interchain packing and π-π stacking happen during the uniaxial stretching process. As such, compared to pristine PI membrane, the stretched membranes show better mechanical and thermal stability, especially for the one with higher stretching ratio. In addition, owing to the increased packing density of polymer chains, the highly stretched membrane of 40%-PI shows significantly improved gas perm-selectivity by 32.8%, 24.3%, and 12.6% for He/CH4, H2/CH4, and CO2/CH4 gas pairs, respectively, in comparison to pristine membrane. Furthermore, 40%-PI exhibits much higher gas permeability retention rate than that of other membranes after three months' aging. We expect that this work can offer polymer materials processing guidance for the preparation of high-performance gas separation membrane in future.

Role of Rheology in Morphology Development and Advanced Processing of Thermoplastic Polymer Materials: A Review.

This review presents fundamental knowledge and recent advances pertaining to research on the role of rheology in polymer processing, highlights the knowledge gap between the function of rheology in various processing operations and the importance of rheology in the development, characterization, and assessment of the morphologies of polymeric materials, and offers ideas for enhancing the processabilities of polymeric materials in advanced processing operations. Rheology plays a crucial role in the morphological evolution of polymer blends and composites, influencing the type of morphology in the case of blends and the quality of dispersion in the cases of both blends and composites. The rheological characteristics of multiphase polymeric materials provide valuable information on the morphologies of these materials, thereby rendering rheology an important tool for morphological assessment. Although rheology extensively affects the processabilities of polymeric materials in all processing operations, this review focuses on the roles of rheology in film blowing, electrospinning, centrifugal jet spinning, and the three-dimensional printing of polymeric materials, which are advanced processing operations that have gained significant research interest. This review offers a comprehensive overview of the fundamentals of morphology development and the aforementioned processing techniques; moreover, it covers all vital aspects related to the tailoring of the rheological characteristics of polymeric materials for achieving superior morphologies and high processabilities of these materials in advanced processing operations. Thus, this article provides a direction for future advancements in polymer processing. Furthermore, the superiority of elongational flow over shear flow in enhancing the quality of dispersion in multiphase polymeric materials and the role of extensional rheology in the advanced processing operations of these materials, which have rarely been discussed in previous reviews, have been critically analyzed in this review. In summary, this article offers new insights into the use of rheology in material and product development during advanced polymer-processing operations.

Hydrodynamic Modeling of Calender Forming (Pressing) of Sheet and Roll Composites

Statement of the problem. The problem of production of sheet and roll composites necessary for the construction industry in the conditions of roll-calender processing and pressing of polymer materials and reinforcing tape is investigated. The solution of this problem is carried out within the framework of a hydrodynamic model of a stationary, isothermal flow of a viscous, incompressible medium in a flat symmetrical layer between two ideal cylinders (calenders) rotating in opposite directions with equal speeds. The purpose of such a statement is to analyze the stress-strain obtained under calendering conditions, as well as to obtain at the design stage of the molding process the results of calculating a complex of energy-power parameters that allow controlling the calendering process. Results and conclusions. Using the approximate Reynolds equations in the part of the deformable medium in direct contact with the cylinders, assuming that its rheological properties correspond to a Newtonian fluid, analytical expressions are obtained for the force and kinematic parameters of pressing, depending on the thickness of the formed layer and the speed of rotation of the rollers. Based on the equilibrium condition, an expression is obtained for the magnitude of the thrust force that ensures the molding process. It is shown that the value of the rolling friction coefficient decreases with a decrease in the thickness of the layer, the specific spacer force, as well as the angular velocity of rotation.

Modeling of mixing process of the polymer composition in the dynamic mixer of the worm extruder

Mixing processes play an important role in the processing of polymer materials, because the quality of the mixing of the polymer material depends on its level of homogeneity, which in turn affects the quality of the final product. It is another matter when the polymer material consists of two or more components, in this case, the issue of the process of obtaining a homogeneous polymer composition becomes extremely acute. In order to improve the quality of the final product and justify the design and technological parameters of the mixing zone, it is necessary to investigate the regularity of the quality of mixing in a dynamic mixer of the CTM worm extruder type.
 According to existing works on determining the quality of mixing of polymeric material, the difference in concentrations of one of the components in different cross-sections along the length of the channel can be used as a criterion for homogeneity of mixing.
 Numerical modeling of the process of mixing the polymer composition in the dynamic mixer installed in the dosing zone of the worm extruder, which is equipped with an additional injection device that supplies the additional component to the dynamic mixing zone through the injection channel located in the body of the worm extruder, was carried out. Calculations were carried out on the basis of the finite element method (FEM) using the ANSYS software complex.
 A mathematical model of the process of mixing the polymer composition in a dynamic mixer of the CTM type of a worm extruder with the addition of an additional component, which is identical in density and viscosity to the main polymer material and can differ only in a certain feature that does not affect the properties of the components, such as color, has been developed. Moreover, the properties were set in such a way that the temperature distribution of the mixture was completely determined by the convective component, that is, it resulted only from the conditions of the mechanical movement of the volumes of the components.
 The dependence of the homogeneity of the polymer composition as a result of mixing on the technological and design parameters of the dynamic mixer of the CTM type was obtained. The research was carried out at different speeds of rotation of the mixer rotor and at different speeds of supplying the additional component. The movement of the components of the mixture was determined by their flow rate at the entrance to the main channel and at the entrance to the additional injection channel.
 The most optimal technical characteristics were selected in order to achieve the best level of uniformity.

Shish-kebab crystallites initiated by shear fracture in bulk polymers: 2. Crystallization on shearing

Shish-kebab crystallites are initiated by the oriented precursors of the ordered structures in the flow processing of polymer materials. In our previous work, we have proposed that the sporadic local events of shear fracture and their memory are responsible for the heterogeneous initiation of shish-kebab crystallites in the shear flow of bulk polymers. Upon the cessation of the Poiseuille-flow-like force field in the binary polymer blends of two chain lengths, our dynamic Monte Carlo simulations demonstrated the formation of precursor and shish-kebab crystal structure at a low temperature. In the present work, we further investigated the boundary conditions of precursor formation at low temperatures while maintaining the force gradients reflecting the global shear rates. The phase diagram of morphological features upon the variations of temperatures and force gradients reveals that steady shish precursors survive at higher temperatures and larger force gradients than the region for shish-kebab crystallites, appearing as responsible for the subsequent shish-kebab formation upon cooling with or without shear cessation. The results are consistent with the related experimental observations and evidence the pre-ordering structure existing before shear-induced polymer crystallization.

A review on use of elemental sulphur in the synthesis of sulphur-based polymers

Sulfur is a plentiful and bioactive component that has been employed in a variety of industries. Despite being a plentiful and affordable chemical substrate, starting materials for chemical synthesis rarely utilise elemental sulphur. Nanoparticles have attracted the attention of researchers due to their widely differing physicochemical features from their bulk materials. Nanosulfur is produced via a nanotechnology process that takes use of structural parameters. Sulfur has been utilized in a variety of industries due to its abundance and biological activity. Through ring-opening polymerization, sulphur can be further converted into polymeric sulphur, which is utilised as a rubber vulcanizing agent.when inverse vulcanization is done for elemental sulphur with different monomeric unitswhich resulted into numerousiproperties. Chemical, structural, and kinetic analyses, as well as temperature,&mechanical basedapplications, used to adjust the characteristic of S-based polymers. Particularly, a number of sulphur composites were synthesized that performed satisfactorily. Here, we discuss some basic techniques for producing chemically inert and workable polymeric materials, and the processtermed as inverse vulcanization and processable polymeric materials. This method allowed sulphur to be converted into processable copolymer forms with controlled thermomechanical properties, resulting in well-defined sulphur-rich micro-patterned films produced by imprint lithography. Inverse vulcanization was employed to synthesise sulphur-based polymeric polymers from sulphur feedstock, elemental sulphur, and Botryococcene, sustainable alga oil. New ways for using elemental sulphur as a feedstock for innovative polymeric materials have recently been developed. In this review, we will look at how polymers could used as potential materials in Lithium-Sulphur cells. This structural and property study gives fundamental knowledge for future operation. Current advancements in the polymerization of elemental sulphur to produce polymers with high sulphur content are discussed in this paper.

DEVELOPMENT OF IMPROVED ROBOTICS EXTRUDER LOADING SYSTEM

The relevance of the study is due to the fact that the loading of granulated polymer material into the working hopper of extruders is mainly carried out manually from bags by production operators. The capacity of working hoppers of extruders is limited due to the fact that with a significant height of the bulk material, an increase in static pressure occurs in the lower layers, which leads to the formation of vaults, uneven supply of polymer into the material cylinder and deterioration of the quality of products. Since the work process of extrusion is continuous and lasts an entire work shift, there is a need to constantly control the filling level of the work hoppers of the extruders. The paper proposes a robotic extruder loading system for the processing of thermoplastic polymer materials into long products (pipes, profiles, films, etc.). The paper proposes a system for loading one or more extruders, which contains a large hopper loaded with raw materials for an entire work shift. From this hopper, the working hopper of the extruder is automatically filled with the help of a screw feeder. Automatic monitoring of the filling status of the hoppers is carried out by a microcontroller with the help of raw material level sensors. The object of research is the process of automatic control of periodic loading of loose materials into technological machines. The subject of the research is a robotic system for loading granulated polymers into the working hoppers of extruders. The purpose of the research is to develop a control system for devices for periodic dosing of granular polymer materials and loading them into working hoppers of limited capacity, which can be used in extruders. The task of the work is an analytical study of the effectiveness of the application of extruder loading systems based on a screw feeder and the development of its design and automatic control scheme. The methodological and theoretical basis of the research are the basic provisions of the theory of automatic control of technological processes, the design of transport equipment for loose media, and the basis of the calculation of machine parts. A scientific novelty is that the work proposed for the first time a device for automatic control of the extruder loading system based on a microcontroller with the possibility of programming the work algorithm. The results of the work can be used to create new systems for controlling the operation of equipment for processing polymer materials and creating new designs. The methodological and theoretical basis of the research are the basic provisions of the theory of automatic control of technological processes, the design of transport equipment for loose media, and the basis of the calculation of machine parts. A scientific novelty is that the work proposed for the first time a device for automatic control of the extruder loading system based on a microcontroller with the possibility of programming the work algorithm. The results of the work can be used to create new systems for controlling the operation of equipment for processing polymer materials and creating new designs.

Influence of cutting ceramics on the formation of the thermoplastics supramolecular structure

The question of the efficiency of turning processing of thermoplastic polymer materials with cutting ceramics is considered. The fact of a decrease in the values of the cutting force when turning the investigated thermoplastics with a tool made of ceramic material KNT16 was experimentally established. It has been experimentally proven that turning caprolon and fluoroplastic using a KNT16 cermet cutting insert leads to the formation of a supramolecular structure of a high degree of homogeneity.

Mathematical modeling of the influence of technological parameters of rotary molding on the amplitude of the ultrasonic bottom signal

In recent years, the processing of polymer materials has undergone significant changes due to the introduction of digital technologies. This article discusses the integration of high-tech methods and tools that ensure reliability, flexibility and optimization of production processes. In particular, emphasis is placed on the choice of non-destructive testing methods to ensure product quality, especially in the production of polymer products by rotary molding. The article discusses the problems associated with incomplete sintering and thermal oxidative decomposition of polyethylene, which have a significant impact on the quality of products. Traditional methods of control, such as visual inspection and ultrasound control, are presented, and their limitations are discussed. The main attention is paid to the application of the ultrasonic method of non-destructive testing to detect incomplete sintering of polyethylene. The authors propose a formula based on probabilistic-deterministic planning, which takes into account the combined effect of temperature and plastic thickness on the amplitude of the ultrasonic signal. This formula demonstrates high reliability, estimated by the coefficient of nonlinear multiple correlation. The use of non-destructive testing methods in the production of polymer products by rotary molding allows us to ensure high quality products and prevent possible breakdowns and accidents during operation. This article represents an important contribution to the field of quality control of polymer products and opens up new opportunities for optimizing production processes.