Surface Of Polymeric Materials Research Articles

Study on cavitation erosion mechanism of UHMWPE and PTFE

Polymer materials possess low density, high strength, corrosion resistance, and excellent cavitation erosion resistance. As a result, they are widely used in marine, water conservancy, and other engineering equipment as replacements for metal materials. However, polymer friction pairs working in a water environment for an extended period are easily damaged by cavitation erosion. In this work, the cavitation behavior of polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE) in deionized water and seawater is investigated through experiments and computational fluid dynamics (CFD) simulations. The results indicate that the cavitation erosion resistance of UHMWPE is significantly better than that of PTFE, and the UHMWPE has four cavitation process stages, while the PTFE has only three cavitation stages. 316L counterparts in the seawater corrosion and cavitation coupling effect of a large number of metal particles off and wash polymer material surface, so that the cavitation erosion of PTFE and UHMWPE is more serious in seawater environment. CFD simulation demonstrates that the cavitation erosion zone under the radiator shows a semicircular distribution. Meanwhile, the formation of ring-shaped cavitation pit is related to the distribution of bubbles on the surface of the radiator. The cavitation rate of PTFE and UHMWPE is slowed down by the “water cushion effect”.

Crystallization ripening and erosion of calcium oxalate under the effect of bacteria and a polymer materials surface.

As typical examples of pathological biomineralization, urinary stones and stent encrustation have been associated with bacteria, yet the underlying mechanisms remain unclear. In this study, the effect of Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus on the nucleation and growth of calcium oxalate crystals both in solution and on material surfaces in vitro was investigated. Both bacteria can promote calcium oxalate crystallization, and E. coli shows a prominent ability to boost the nucleation and growth rate. Interestingly, we discovered an Ostwald ripening phenomenon after the initial nucleation on the material surfaces, where larger particles emerge upon the disappearance of small nuclei particles, evident in the case of S. aureas. Over an extended period of time, erosion and disintegration of the crystals was observed when bacteria were involved. Based on these understandings, we developed a new functional surface by synthesizing an antibacterial polypeptoid in-house and utilizing polyurethane as the substrate material. This surface exhibits a synergistic effect that inhibits the formation of calcium oxalate crystals. This study helps to elucidate the role of bacteria in calcium oxalate biomineralization and supports further development of treatment approaches such as anti-encrustation polymer materials.

Establishment of urinary catheter materials antibacterial efficacy evaluation platform in pigs

Urinary catheters are one of the common invasive medical catheters, mostly composed of high-polymer materials such as polyurethanes. During clinical use, the high friction between the catheter material surface and tissues can lead to tissue damage, patient discomfort, and pain during insertion or removal. Moreover, due to the hydrophobic nature of the polymer material surface, there is a risk of urinary tract infections (CTIs) caused by problems such as protein adsorption and bacterial infection upon insertion into the body. Prolonged indwelling time of urinary catheters in the body increases the probability of other complications, potentially leading to life-threatening consequences and imposing medical burdens. Therefore, the purpose of this study was focused on the insertion of the Escherichia coli (E. coli, 1 × 105 CFU/mL)-coated urinary catheter to implant into a female pig’s urethra for establishing the urinary catheter materials antibacterial efficacy evaluation platform in pigs. Results were shown that during the experimental period, the week 1 and week 2 average pig’ body temperature were 39.4 ± 0.6°C and 39.1 ± 0.2°C, respectively. The average pig’s body temperature was normal and there was no significant differences in body temperature at week 1 and week 2 urinary catheter implanted-experiment period. Moreover, the clinical observation of the pigs showed that their vitality, appetite, and excretion were all normal, and they survived until the end of the experiment without presenting any abnormal clinical symptoms. In addition, E. coli in urine culture respectively showed 0.95 ± 0.03 × 105 CFU/mL, 1.23 ± 0.03 × 105 CFU/mL, 1.43 ± 0.04 × 105 CFU/mL, 1.75 ± 0.08 × 105 CFU/mL, and 1.91 ± 0.09 × 105 CFU/mL on day 0, 3, 7, 10, and 14 of urinary catheter implantation. As time progressed after urinary catheter implantation, there was an increasing trend in E. coli counts. Staining with crystal violet for urinary catheter showed that the urinary catheter wall was positive for crystal violet staining. E. coli isolation and counts from biofilm on inside and outside of urinary catheter respectively showed 5.10 ± 0.10 × 105 CFU/mL and 7.50 ± 1.08 × 105 CFU/mL on day 14 of urinary catheter implantation. As time progressed after urinary catheter implantation, there was an increasing trend in E. coli counts. Finally, the pathological interpretation of the urinary tract indicates that in the tissue morphology of the bladder, there is observed a localized mild shedding of superficial and intermediate layer cells in the transitional epithelium of the ureteral stent group, with only basal cells remaining connected to its submucosa. There are no significant pathological changes observed in the tissue morphology of the urethra and kidneys. According to the results of this study, a urinary catheter materials antibacterial efficacy evaluation platform in pigs has successfully established, which can be provided for R&D of urinary catheter antibacterial materials.

Rhamnolipids‐based glycosylated coating for preparing non‐charging polymeric materials surfaces

AbstractPolymer materials are typical insulators that are easily charged by contact electrification. Static charge generated by contact electrification on their surfaces can lead to lots of undesirable consequences, including a reduction in efficiency of manufacturing processes, damage to equipment, and even explosions. Thus, it is important to develop effective strategies to prevent the generation of static charge when surfaces of polymer materials come into contact. Here, we coated polymer materials with rhamnolipids (RLs) to create non‐charging surfaces. This innovative technique, based on glycosylated coatings using RLs, offers a universal solution that can be easily applied to a wide range of polymeric materials conferring resistance to surface charging via contact electrification. The amount of static charges generated was found to reduce dramatically in both low (~15%) and high (~60%) humidity situations. The reduction of charge is due to either or both of the following two mechanisms: by increasing surface conductivity driven by the hydrophilic groups of the RLs molecules, and or by their radical‐scavenging properties. Predictably, this new effective strategy is ideal for producing antistatic dipping and spray solution for various practical applications.

Surface modification strategies for improved hemocompatibility of polymeric materials: a comprehensive review.

Polymeric biomaterials are a widely used class of materials due to their versatile properties. However, as with all other types of materials used for biomaterials, polymers also have to interact with blood. When blood comes into contact with any foreign body, it initiates a cascade which leads to platelet activation and blood coagulation. The implant surface also has to encounter a thromboinflammatory response which makes the implant integrity vulnerable, this leads to blood coagulation on the implant and obstructs it from performing its function. Hence, the surface plays a pivotal role in the design and application of biomaterials. In particular, the surface properties of biomaterials are responsible for biocompatibility with biological systems and hemocompatibility. This review provides a report on recent advances in the field of surface modification approaches for improved hemocompatibility. We focus on the surface properties of polysaccharides, proteins, and synthetic polymers. The blood coagulation cascade has been discussed and blood - material surface interactions have also been explained. The interactions of blood proteins and cells with polymeric material surfaces have been discussed. Moreover, the benefits as well as drawbacks of blood coagulation on the implant surface for wound healing purposes have also been studied. Surface modifications implemented by other researchers to enhance as well as prevent blood coagulation have also been analyzed.

Investigation of the influence of the environment on the electrical properties of textile clothing materials

Investigation that Elevated levels of static electricity build-up on the surfaces of work clothes, different technological structures, and polymeric materials can cause disruptions to the techno-bio system, resulting in adverse physiological effects in humans, accidents caused by humans, and environmental disasters. Under conditions of low temperatures, electrostatic charge on polymeric materials is intensively generated. Synthetic materials have an increased ability to electrify. The processes were studied the mechanisms of the occurrence of a electricity an polymer materials of clothing in winter. The logical structure of the model of the formation of an electrostatic field on the surface of polymer materials of objects in environmental conditions during a snowstorm has been developed. A set of materials for experimental thermal protective clothing was investigated. The findings from the investigation into the process of electrification in the layers of materials used to make thermally protective clothing are gathered and given. As follows from the graphs, the limiting value of the electrostatic field strength can occur already with an external field of 15000 V/m. The formation of charges is facilitated by the physical conditions of the snowstorm electrification in the system of polymer structures.

Supercritical CO2 Assisted Ni-P Electroless Plating of PET Components with Complex 3D Structures

There is an increasing demand of methodologies to metallize complex polymer materials for application in electronics such as wearable devices and robotic products. In various metallization methods, electroless plating is a powerful and promising approach to meet this demand. The present conventional electroless plating requires pretreatment steps to deposit catalyst onto surfaces of polymer materials, which results in damages to their surfaces and also deformation of their shape because of the usage of strong acidic solvents. Furthermore, the adhesion strength between the polymer material and the metal layer is insufficient. To overcome these problems, a catalyzation step using supercritical carbon dioxide (sc-CO2) as the solvent is proposed.[1] The sc-CO2-assisted catalyzation enables a deep impregnation of catalysts into the polymer material without the pretreatment step, and this enhances the adhesive properties of the deposited metal on the polymer. By the sc-CO2-assisted catalyzation, electroless Ni-P plating of polyethylene terephthalate (PET) is realized. [1] Metallization of polymer materials with complex 3D structures is a more attractive topic, but it is widely accepted to be more difficult than film structures. Also, application the electroless plating via sc-CO2-asssited catalyzation to 3D-structured polymer materials remains unexplored. In this presentation, we report Ni-P plating of PET samples having complex 3D structures by the sc-CO2-assisited catalyzation process.A PET based material with a concavo-convex structure was designed and fabricated by the processing machine as shown in Figs. 1(a)–(b). Sc-CO2-assisted catalyzation process was performed in a high pressure reactor[1] containing palladium (II) hexafluoroacetylacetonate (Pd(C5HF6O2)2) as the palladium catalyst source at 70 °C under 15 MPa for 2 h. After the catalyzation process, the reactor was cooled to room temperature while maintaining the pressure in the reactor, and then the pressure in the reactor was reduced to atmospheric pressure. The collected PET sample from the reactor was kept under ambient atmosphere for two weeks, and then it was subjected to electroless Ni-P plating at 70 ℃ for 10 min.Fig. 1(c) shows the PET sample obtained after the sc-CO2-assisted catalyzation process followed by the post-treatment process. The volume of the catalyzed PET sample was scarcely changed. On the other hand, the post-treatment processes performed under the different conditions were found to cause undesired swelling and white turbidity of the PET sample, presumably because of microbubbles derived from residual CO2 in the PET. Fig. 1(d) shows an image of Ni-P successfully metallized on the PET surface. The electrical resistance of the Ni-P/PET material was 8.7 Ω, which is acceptable for electronic device applications. From these results, we concluded that sc-CO2-assisted catalyzation is applicable to metallization of PET materials with complex 3D structures. Reference [1] P.-W. Cheng, C.-Y. Chen, T. Ichibayashi, T.-F.M. Chang, M. Sone, S. Nishimura, J. Supercrit. Fluids 180 (2022) 105455. Figure 1

Application of surface-layer matrix-assisted laser desorption/ionization mass spectrometry imaging to pharmaceutical-loaded poly(ester urea) films

Polymer thin films are often used in transdermal patches as a method of continuous drug administration for patients with chronic illness. Understanding the drug segregation and distribution within these films is important for monitoring proper drug release over time. Surface-layer matrix-assisted laser desorption/ionization mass spectrometry imaging (SL-MALDI-MSI) is a unique analytical technique that provides an optical representation of chemical compositions that exist at the surface of polymeric materials. Solvent-free sublimation is employed for application of matrix to the sample surface, so that only molecules in direct contact with the matrix layer are detected. Here, these methodologies are utilized to visualize variations in drug concentration at both the air and substrate interface in pharmaceutical-loaded polymer films.

Effect of carbon black components on rolling mechanical properties of tread rubber material by using improved digital image correlation

AbstractThe rolling and sliding state of the tread rubber material within contact patch was very important to the handling stability and safety of the vehicle. In this paper, first, the absolute coordinate system was introduced into the digital image correlation method, which improved the ability of the traditional digital image correlation method to solve the large deformation of polymer material surface. Second, a new calculation method of rolling friction coefficient based on the brush model was proposed. Third, a non‐contact full‐field rolling dynamics experimental device was developed to study the effects of carbon black components, rotational speed and vertical load on the rolling mechanical characteristics of tread rubber material. On this basis, the rolling mechanical characteristics of tread rubber material with different formulations were obtained by analyzing the distribution properties of global strain rate, full‐field longitudinal speed and full‐field longitudinal acceleration and the variation laws of transverse/longitudinal strain rate, trajectory of marked points, stress‐strain hysteresis curve and rolling friction coefficient. Finally, the influence mechanism of carbon black composition on rolling mechanical properties of tread rubber material was revealed.

Elastic Modulus of a Carbonized Layer on Polyurethane Treated by Ion-Plasma

Nanocoatings formed by various plasma and chemical methods on the surface of polymeric materials have unique properties. However, the applicability of polymeric materials with nanocoatings under specific temperature and mechanical conditions depends on the physical and mechanical properties of the coating. The determination of Young's modulus is a task of paramount importance since it is widely used in calculations of the stress-strain state of structural elements and structures in general. Small thicknesses of nanocoatings limit the choice of methods for determining the modulus of elasticity. In this paper, we propose a method for determining the Young's modulus for a carbonized layer formed on a polyurethane substrate. For its implementation, the results of uniaxial tensile tests were used. This approach made it possible to obtain patterns of change in the Young's modulus of the carbonized layer depending on the intensity of ion-plasma treatment. These regularities were compared with regularities of changes in the molecular structure of the surface layer caused by plasma treatment of different intensity. The comparison was made on the basis of correlation analysis. Changes in the molecular structure of the coating were determined from the results of infrared Fourier spectroscopy (FTIR) and spectral ellipsometry.

Effects of Different Polymeric Materials on the Bacterial Attachment and Biofilm Formation in Anoxic Fixed-Bed Biofilm Reactors

Six biofilm carriers with different polymer were studied in fixed-film systems under anoxic conditions. Different media of polymers influence wastewater treatment performance. The aim of this study was to investigate different polymeric materials, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), high-density polyethylene (HDPE), and polymethyl methacrylate (acrylic), that affect bacterial attachment and biofilm formation in biofilm-based wastewater treatment technologies. Water contact angle (WCA) measurement was employed to analyze the role of wetting (hydrophilic/hydrophobic) of polymeric material surfaces in the initial phase of bacterial attachment. The increase of biofilm formation during the observation was determined by gravimetric (total attached solid) and microscopic (SEM and CLSM) analysis. The results showed the value for WCA of PET < HDPE < PVC < PP < acrylic, which indicated that a higher hydrophilicity surface leads to a higher total attached solid (TAS), biofilm formation rate, and biofilm thickness on the surface of media. The hydrophilic material (i.e., PET and HDPE) demonstrated wastewater treatment performance better than slightly hydrophilic material (i.e., PVC, PP, and acrylic) under a steady-state period (over an 80-day operation). The data showed a positive correlation between hydrophilic material and COD, NH4+-N, and TP removal. Hydrophilic material was beneficial for a fast start-up and stable biofilm formation of a fixed-bed biofilm reactor. PET media showed feasible polymer types compared to HDPE, PVC, and PP; thus, it can be used as an alternative biofilm carrier media in a larger-scale application. The findings of this study highlighted the polymeric material type has a significant effect on the performance of fixed-bed wastewater treatment.

Polymeric Heart Valves Will Displace Mechanical and Tissue Heart Valves: A New Era for the Medical Devices.

The development of a novel artificial heart valve with outstanding durability and safety has remained a challenge since the first mechanical heart valve entered the market 65 years ago. Recent progress in high-molecular compounds opened new horizons in overcoming major drawbacks of mechanical and tissue heart valves (dysfunction and failure, tissue degradation, calcification, high immunogenic potential, and high risk of thrombosis), providing new insights into the development of an ideal artificial heart valve. Polymeric heart valves can best mimic the tissue-level mechanical behavior of the native valves. This review summarizes the evolution of polymeric heart valves and the state-of-the-art approaches to their development, fabrication, and manufacturing. The review discusses the biocompatibility and durability testing of previously investigated polymeric materials and presents the most recent developments, including the first human clinical trials of LifePolymer. New promising functional polymers, nanocomposite biomaterials, and valve designs are discussed in terms of their potential application in the development of an ideal polymeric heart valve. The superiority and inferiority of nanocomposite and hybrid materials to non-modified polymers are reported. The review proposes several concepts potentially suitable to address the above-mentioned challenges arising in the R&D of polymeric heart valves from the properties, structure, and surface of polymeric materials. Additive manufacturing, nanotechnology, anisotropy control, machine learning, and advanced modeling tools have given the green light to set new directions for polymeric heart valves.

Improving the wear resistance of polyvinyl chloride surface by using the friction stir processing technique

Friction Stir Processing is considered one of the essential methods for improving the surfaces of polymeric materials by adding reinforcing particles in specific ratios to form a composite material with better surface properties than the properties of the base material. The Friction Stir Processing technique was employed in the present investigation to introduce graphite particles onto the polyvinyl chloride surface. Various volumetric ratios of 5, 8, 11, 14, 17, and 20% were used for the incorporation of graphite particles. Mechanical tests (flexural strength, hardness, and wear resistance) were carried out. The experiments demonstrated a noteworthy enhancement in the measured characteristics, with the most notable outcomes observed when the graphite content was increased by 20%. Consequently, this investigation determined that applying the Friction Stir Processing technique effectively reinforced the polyvinyl chloride surface by forming a successful surface composite.

Chain Movements at the Topmost Surface of Poly(methyl methacrylate) and Polystyrene Films Directly Evaluated by In Situ High-Temperature Atomic Force Microscopy.

The surfaces of polymeric materials are thermodynamically unstable, and the glass-transition temperature (Tg) is significantly lower than that in the bulk material. However, the mobility of the chains at the top of the surface has never been directly evaluated. In this study, the movements of the topmost chains of poly(methyl methacrylate) (PMMA) and polystyrene (PS) bulk films were observed in situ at high temperatures with atomic force microscopy in tapping mode. PMMA and PS chains started moving at ∼97 and ∼50 °C, respectively, which were slightly and significantly below the values of their bulk Tg (PMMA, 108 °C; PS, 104 °C), respectively. The activation energies of the apparent diffusion constants of PMMA and PS, derived by particle image velocimetry analysis, were 193 and 151 kJ mol-1, respectively, and reasonable for the glass transition. Movements of isolated PMMA chains deposited on a PMMA film by the Langmuir-Blodgett technique were also observed and confirmed to be essentially the same as those on the PMMA film surface.

The Distribution and Evolution of Refractive Index in a Polystyrene Whispering Gallery Microcavity during Glass Transition

AbstractThere is limited knowledge on the evolution of physical and chemical parameters near the surface of polymer materials at the microscopic level during glass transition, owing to the complexity of this process. For example, the distribution and evolution of the refractive index near the surface of polymer materials during glass transition are thus far unknown; however, this information is necessary for the design of optical micro‐elements based on polymer materials. Herein, a strategy is proposed to achieve the expression of the refractive index as a function of depth and temperature inside a polystyrene microsphere. The difference in the wavelength shifts between two whispering gallery modes with different radial orders is employed to detect the evolution of the refractive index during the glass transition. A model is established based on experimental observations and further confirmed by numerical simulations. It is believed that the results obtained can assist with the design of polymer optical micro‐elements and systems as well as sensing applications of whispering gallery microcavities.

Functionalization of Polymer Surface with Antimicrobial Microcapsules.

The development of antimicrobial polymers is a priority for engineers fighting microbial resistant strains. Silver ions and silver nanoparticles can assist in enhancing the antimicrobial properties of microcapsules that release such substances in time which prolongs the efficiency of antimicrobial effects. Therefore, this study aimed to functionalize different polymer surfaces with antimicrobial core/shell microcapsules. Microcapsules were made of sodium alginate in shell and filled with antimicrobial silver in their core prior to application on the surface of polymer materials by dip-coating methodology. Characterization of polymers after functionalization was performed by several spectroscopic and microscopic techniques. After the characterization of polymers before and after the functionalization, the release of the active substances was monitored in time. The obtained test results can help with the calculation on the minimal concentration of antimicrobial silver that is encapsulated to achieve the desired amounts of release over time.

Plasma Flows From Linear High-Voltage Nanosecond Vacuum Discharges on the Surface of Polymer Materials at 2–6 kA

Particle flow from vacuum flashover on surface of PTFE, PMMA, and PE initiated by 60-kV nanosecond pulses in self-breakdown mode is studied in this work in the range of discharge currents of 2–6 kA. The feature of this work is changing the discharge current at the constant working voltage (~60 kV). The discharge current is varied by changing a ballast resistor. The time lag between voltage application and current rise is ~12 ns for all the values of the discharge current. This lag corresponds to the stage of conductive channel formation (high-voltage stage) and depends only on working voltage of the generator. In contrast to the low-voltage experiments (~1–5 kV) with external ignition, in our case, plasma flow characteristics depend only on intrinsic properties of the breakdown. The novelty of the proposed approach is that all the measurements are carried out at high repetition rate of pulse application (30–100 Hz). We obtained the dependence of particle flow thrust, mass loss, and share of ion component on the value of the discharge current. The results show that there is a share of the ion beam, intensity of which does not depend on the discharge current. Presumably, these ions are generated at the high-voltage stage of the flashover process. The thrust is directly proportional to the charge passed through the discharge channel. It indicates that the key factor in raise of particle flow intensity is the widening of the discharge channel at higher currents. Some of the results are of practical interest for the development of high-voltage pulsed plasma thrusters.

Sustained effect of dry water in a thermal environment after fire extinguishing: Fuel surface coating methods

The elimination of heat and smoke hazards during the polymer combustion process is still challenging. In this work, we created a thermal environment using a fire propagation apparatus (FPA) and studied the sustained effect of dry water coated on the surface of polymer materials after fire extinguishing. The tests indicated an effective burnback delay and the reduction of heat and smoke hazards. This approach significantly increased the ignition time and reduced the heat release rate and the smoke and carbon monoxide production rate compared to fuel without dry water coating. The radiation intensity influenced the sustained performance of dry water, i.e., the larger the radiation intensity, the worse sustained performance. The sustained performance was also improved by using an aqueous solution as inner material. A low mass fraction of the aqueous solution yielded an improved sustained performance in the initial combustion stage. Furthermore, the gelation of dry water with the inner aqueous solution could balance the structural strength and the thermal shielding performance. These results have implications for designing a technical program toward longer escape and rescue times for stranded persons and firefighters.

Selective Fluorination of the Surface of Polymeric Materials after Stereolithography 3D Printing.

With the microfluidics community embracing 3D resin printing as a rapid fabrication method, controlling surface chemistry has emerged as a new challenge. Fluorination of 3D-printed surfaces is highly desirable in many applications due to chemical inertness, low friction coefficients, antifouling properties, and the potential for selective hydrophobic patterning. Despite sporadic reports, silanization methods have not been optimized for covalent bonding with polymeric resins. As a case study, we tested the silanization of a commercially available (meth)acrylate-based resin (BV-007A) with a fluoroalkyl trichlorosilane. Interestingly, plasma oxidation was unnecessary for silanization of this resin and indeed was ineffective. Solvent-based deposition in a fluorinated oil (FC-40) generated significantly higher contact angles than deposition in ethanol or gas-phase deposition, yielding hydrophobic surfaces with contact angle >110° under optimized conditions. Attenuated total reflectance-Fourier transform infrared spectroscopy indicated that the increase in the contact angle correlated with consumption of a carbonyl moiety, suggesting covalent bonding of silane without plasma oxidation. Consistent with a covalent bond, silanization was resistant to mechanical damage and hydrolysis in methanol and was stable over long-term storage. When tested on a suite of photocrosslinkable resins, this silanization protocol generated highly hydrophobic surfaces (contact angle > 110°) on three resins and moderate hydrophobicity (90-100°) on the remainder. Selective patterning of hydrophobic regions in an open 3D-printed microchannel was possible in combination with simple masking techniques. Thus, this facile fluorination strategy is expected to be applicable for resin-printed materials in a variety of contexts including micropatterning and multiphase microfluidics.

FORMATION OF ANTIMICROBIAL CARBON AND FLUOROCARBON COATINGS USING PREDICTIVE MODELING OF THEIR PROPERTIES

The article discusses the technology of forming carbon and fluorocarbon coatings of nanometer thickness by means of ion-plasma technology at reduced pressure on the surface of polymeric materials in order to protect them from biodegradation. To debug the technology, a mechanism was used that uses neural networks for the purpose of mathematical predictive modeling of the antimicrobial properties of the formed films. This mechanism makes it possible to predict the presence of antimicrobial properties in fluorocarbon and carbon coatings formed at various technological parameters, without carrying out field experiments, with an accuracy of 71% when considering 5 technological factors.