Epoxy Binder Research Articles

Radiographic Inspection of Carbon Fiber-Reinforced Polymer Composites (Laminates) with Epoxy and PEEK Binders After Impact and Subsequent Compression Loading

An approach to detecting discontinuities in carbon fiber-reinforced polymers, caused by impact loading followed by compression testing, was developed. An X-ray sensor-based installation was used, while some algorithms were developed to improve the quality of the obtained low-contrast radiographic images with negligible signal-to-noise ratios. For epoxy/AF (#1) composite subjected to a “high-velocity” steel-ball impact with subsequent compression loading, it was not possible to detect discontinuities since the orientation of the extended zone of interlayer delamination was perpendicular to the irradiation axis. After drop-weight impacts with subsequent compression loading of epoxy/CF (#2) and PEEK/CF (#3) composites, the main cracks were formed in their central parts. This area was reliably detected through the improved radiographic images being more contrasted compared to that for composite #3, for which the damaged area was similar in shape but smaller. The phase variation and congruency methods were employed to highlight low-contrast objects in the radiographic images. The phase variation procedure showed higher efficiency in detecting small objects, while phase congruency is preferable for highlighting large objects. To assess the degree of image improvement, several metrics were implemented. In the analysis of the model images, the most indicative was the PSNR parameter (with a S-N ratio greater than the unit), confirming an increase in image contrast and a decrease in noise level. The NIQE and PIQE parameters enabled the correct assessment of image quality even with the S-N ratio being less than a unit.

Eco-friendly and cost-effective epoxy binder for polymer mortar utilizing oregano oil-based hardener

Polymer mortar, consisting of a polymer binder and aggregates, offers superior properties such as enhanced strength, durability, and corrosion resistance compared to the traditional cement-based mortars. Within the polymer-based mortar, epoxy resin is one of the most commonly used resins owing to its high performance. However, its widespread adoption is hindered by costs and environmental concerns, particularly the dependence of bisphenol A-containing epoxide, a substance harmful to human health. In this work, a novel epoxy hardener derived from oregano oil (OEO) was developed to create a more eco-friendly and cost-effective binder for polymer mortar. The inclusion of OEO-based hardeners reduced the viscosity of the binder and accelerated the curing process. The Mannich base structure of the hardener induced more reactive sites in the epoxy system, resulting in a denser crosslinked network. Polymer mortars fabricated with this novel hardener exhibited improved mechanical properties, bonding strength, and corrosion resistance compared to conventional epoxy mortars. Scanning electron microscopy images also revealed a stronger interfacial bond between the epoxy resin and the aggregates. This study demonstrates the potential of OEO-based hardeners to enhance the performance of epoxy binders, providing a sustainable alternative for polymer-based mortar applications.

Transmission and Reflection Properties of Iron Pyrite-Epoxy Resin Composite for Electromagnetic Applications.

This study examines the electromagnetic properties of a composite material composed of iron pyrite (FeS2) and epoxy resin, mixed in a 3:2 weight ratio to create a 10 cm3 cube. The research analyzes transmission and reflection coefficients and band gap parameters to determine its viability as an antenna substrate for electromagnetic wave applications. The composite displays a tunable band gap of 1.3 eV, enabling selective absorption and emission of electromagnetic radiation. The transmission coefficient achieved 90% throughout a frequency range of 1 GHz to 15 GHz, whilst the reflection coefficient was measured at 10%, significantly reducing reflecting losses. The epoxy resin binder was essential for preserving structural integrity and augmenting the dielectric characteristics of the composite, thereby raising transmission efficiency. UV-Vis spectroscopy showed an absorption value of 0.875% at the band gap, indicating efficient interaction with UV energy. The S21 transmission coefficient ranged from -10 dB to -80 dB, with a maximum of -40 dB at 6 GHz, indicating strong energy transfer capability for antenna applications. The S21 values exhibited negligible signal attenuation between 2 GHz and 7 GHz, indicating the material's exceptional suitability for antenna substrates necessitating dependable transmission. The S11 reflection coefficient varied from -5 dB to -55 dB, with substantial decreases between 4 GHz and 14 GHz, when reflection decreased to -45 dB, signifying little signal reflection at essential frequencies. The results underscore the composite's appropriateness for applications requiring high transmission efficiency, little reflection, and effective engagement with electromagnetic waves, especially as an antenna substrate. Measurements were performed using a vector network analyzer (VNA) to obtain the S11 and S21 characteristics, underscoring the material's potential in sophisticated electromagnetic applications.

A novel ultra-light bio-based fiberboard from mexican feather grass for thermal and acoustic insulation in green building construction applications

The use of natural fibers as raw materials for insulation fiberboard production is emerging as a strategy to replace wood fibers. This study developed an ultralightweight natural fiber insulation core fiberboard (CFB) with high mechanical strength, hygroscopic resistance, and excellent acoustic and thermal insulation properties. This study examined the production of CFB, which utilizes Mexican feather grass fibers with an epoxy resin binder across a range of densities of 0.18–0.36 g∙cm−3. Furthermore, the impact of incorporating a reinforcing skin layer of woven glass fibers on the core fiberboard's physical, mechanical, acoustic, and thermal properties was evaluated. All the fiberboard samples exhibited excellent thermal conductivity values (0.048–0.057 W/mK), which increased with increasing panel density (0.18–0.36 g∙cm−3). In addition, all of them displayed superior mechanical properties following the ASTM C208 standard. In terms of climatic resistance of the fiberboards, the results displayed excellent water resistance, exhibiting minimal humidity content (<5 %), thickness swelling (<6.5 %), and a hydrophobic surface, as indicated by the high-water contact angle (>121.96 at 30 s). Sound reduction exhibited a frequency-dependent tendency, with denser and sandwich fiberboards showing greater sound reduction of up to 27.9–36.56 dB at 3150 Hz for CFB-0.36 and SFB-0.52, respectively. Following ASTM C208, both core fiberboards and those coated with woven glass fiber skins (sandwich fiberboards, SFB) met the thermomechanical property requirements for regular and structural wall sheathing applications, respectively. These findings highlight the potential of Mexican feather grass as a bio-based alternative to wood, enabling the production of eco-friendly ultralightweight fiberboards with excellent thermomechanical properties suitable for building construction, such as regular and structural wall sheathing applications and ceiling decorations.

On the physical-mechanical and tribotechnical properties of antifriction carbon fiber based on a modified thermosetting matrix

The physical-mechanical and tribological properties of anti-friction carbon fiber plastic UGET based on low-modulus carbon fabric “Ural T-15R” have been studied in order to increase the magnitude of the ultimate deformation and reduce the elastic modulus through the use of a modified thermosetting matrix ET-4 instead of the traditionally used ET-2.Modes of polymerization and of heat treatment of epoxy binders were selected considering the results of the experiments. Prototypes of prepregs were obtained by solution impregnation on the UPST-1000M line and then processed into PCM by hot pressing. Laboratory samples were made and physical and mechanical tests were carried out to determine the ultimate strength under compression, shear and bending stress under destruction, as well as Charpy impact strength. Steel 20Kh13 and oxidized titanium alloy PT-3V were used as counter body rollers to determine carbon fiber tribosets.It was shown that carbon fiber samples based on chemically modified binder ET-4 with two-stage polymerization and heat treatment mode in the range of 90°C to 180°C both have better physical-mechanical and tribotechnical properties, in contrast with the analogue with a three-stage mode and carbon fiber carbon heat at friction over 20Kh13 steel and oxidized titanium alloy PT-3V.

Control of the parameters of thermosetting binders directly during the molding of products made of polymer composite materials

For aviation binders at the moment there is no necessary methodological base on the basis of which it is possible to control the conditions of their curing by viscosity, reaction rate and glass transition temperature in real time. The paper presents a method of control of thermosetting binder parameters directly during the molding process. The epoxy binder VSE-59 was studied. A mathematical model of the relationship between the frequency maximum parameter of the imaginary component of the electrical impedance and the degree of curing is given, the results of dielectric analysis are compared with laboratory methods (differential scanning calorimetry and rheometry). It is shown that the convergence of the values of the degree of conversion is high. Rheological and dielectric analyses revealed a direct correlation between electrical and rheological properties in the range of injection temperatures. Equations were determined and coefficients were experimentally selected to describe the correlation between viscosity and glass transition temperature and dielectric parameters, which provides the possibility of their control in real time. The obtained results can be used to create a hardware and software base, which makes it possible to control the state of the binder at each moment of the process of forming products from polymer composite materials, as well as to carry out optimization to eliminate the emergence of conditions of uneven polymerization. Realization of the detailed control of the binder state in different parts of the product will allow to carry out verification of calculations, to predict and avoid the occurrence of warping and, accordingly, to increase the quality of composite products.

Design of radio-transparent shelters using an optimized mathematical apparatus for analytical strength calculations

The main aspects of the design of radio-transparent shelters have considered, taking into account the provision of the required strength, mass-centering radio engineering characteristics, as well as the temperature of the environment inside the radome at all stages of product operation. The use of new structural and functional composite materials in modern technology makes it possible not only to reduce the total weight of the structure by 30 – 35%, but also to significantly increase the reliability of operation compared to materials based on epoxy binders. It is promising to use heat-resistant thermosetting binders and materials based on them for the manufacture of friction units that require lubrication and as high-temperature thermal insulation of critical elements of aerospace engineering. Analytical dependences make it possible to select a preliminary RPR design and, at the initial design stage, assign a minimum wall thickness. However, further solution of the complex problem of ensuring the shape, stability and strength using the simulation of the stress-strain state of radio-transparent composite structures is advisable to carry out by the finite element method. The disadvantages of fiberglass include the fragility of the fibers, low density and a tendency to shrink. In this regard, the analysis of materials for the manufacture of fairings for the protection of electronic equipment have currently being carried out and the technique used to analyze the possibility of using fiberglass fairings can be applied to various composite materials.

Assessment of chemical degradation of epoxy resin binder used in the service of the Qin terracotta warriors

Since the Qin terracotta warriors were unearthed, polyamide 650 cross-linked E-44 epoxy resin binder has been employed to bond and restore them. In this paper, the chemical aging of the binders service in indoor natural environment during the past 30 years in the terracotta warriors was studied by means of infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The results indicated that the binders did not emerge the characteristic peak of carbonyl stretching vibration at 1700 cm−1 in the IR spectra of all determined binders, and their thermal decomposition curves did not emerge any abnormal changes, and the thermal decomposition mainly occurred above 300 °C. There are evident ceramic grains attached to the surface of the binders being peeled off for sampling. These results that the binders service in the Qin terracotta warriors did not exhibit an observable chemical aging and still has strong adhesion. Generally, discrepancies were observed between natural aging and accelerated artificial aging due to the ineffectiveness of the latter to reproduce the effects of complex weather conditions. Compared to artificially accelerated aging, the evaluation results in a long-term natural aging of the binder which is used for restoration of the life-size Qin terracotta warriors, providing in the present investigation, are more reliable in terms of predicting the safety of restored terracotta warriors.

Определение прочностных характеристик полимерного ремонтного бандажа для рукавов высокого давления

A comparative analysis of the strength characteristics of high-pressure hoses without damage and with a restored defect in the form of a through cut was carried out. To repair damages of high-pressure hoses, it is proposed to use bandages made of polymer composite materials based on a carbon filament and an epoxy binder. It is shown that the use of high-pressure hoses in hydraulic lines of road construction machines, restored using a polymer bandage, allows one to maintain the operational characteristics of this rubber-technical element.

Performance of optimized composition of epoxy resin adhesive used in High Friction Surface Treatment

The High Friction Surface Treatment (HFST) paving technique is widely employed in engineering practices globally, serving to enhance the long-term anti-skid performance of pavements. However, there still exist significant gaps in research regarding the modified and optimized composition and corresponding content of the polymer binding materials used in HFST, as well as the performance of the pavements laid with modified and optimized blended aggregates during service. To address these issues, this research first modified and optimized the composition ratio of traditional epoxy resin materials. Subsequently, a toughened, high-flow epoxy bonding system suitable for the maintenance of concrete pavements was prepared. Additionally, the study explored the bonding performance of this system with both the cement base surface and aggregates. The results established that the optimal ratio range for the modified epoxy adhesive system is E51 epoxy resin to curing agent to toughening agent to diluent in the proportions of 100: 30–35: 20–30: 5. The experimental group used a high-flow epoxy resin adhesive ratio of E51 epoxy resin: curing agent: toughener: diluent = 100:30:20:5. For control group 1, the ratio of epoxy resin adhesive was E51 epoxy resin: curing agent = 100:30, and for control group 2, the ratio was E44 epoxy resin: curing agent = 1:1. Compared with control groups 1 and 2, the modified epoxy system with the cement base demonstrated a 149 % increase in average pull-off strength and an 18 % increase in average shear strength. Similarly, in comparison with control groups 1 and 2, the modified epoxy system with aggregates exhibited a 174 % increase in average pull-off strength and a 541 % increase in average shear strength. Based on the pull-off and shear test results, it was ultimately determined that the dosage of modified epoxy binder for HFST mixtures should be controlled at 1.0–1.2 kg/m2, and the dosage of aggregate should be controlled at 3.3–4.3 kg/m2. These findings provide valuable insights into optimizing HFST pavement compositions for improved performance and longevity.

TECHNOLOGICAL ASPECTS OF PRODUCTION OF EPOXY ASPHALT CONCRETE BY ADDING CARBON ADDITIVES

Epoxy asphalt concrete is a durable, high-quality material consisting of epoxy resins, hardeners, and the mineral part itself. Accordingly, slow-hardening epoxy asphalt concrete has high physical properties and low sensitivity to temperature changes, which makes it usable as a rigid pavement and applicable even on metal and concrete bridge decks. However, a downside of epoxy asphalt concrete is its ability to gain strength over a long period of operation (up to 1 year). It is a disadvantage when using such coatings in the upper layer of the road surface. In addition, a long period of strength gain during intensive use of the road pavement leads to critical destruction of the pavement itself, plastic deformation, and a reduction in the service life (which may differ much from the standard). Using metal fibre substantially increases the strength and keeps the area from collapsing. The use of metal elements can significantly reduce the performance of the tires of vehicles that will drive on the road and even create a hazard in the event of destruction of the epoxy asphalt concrete area. Using epoxy binders notably increases the strength characteristics of road materials, especially at high temperatures, and boosts their ability to resist rutting. At the same time, the characteristics of epoxy concrete do not decrease during operation and at low temperatures, which indicates the versatility of such a material. The only drawback that cancels out all the positive features of epoxy asphalt concrete is its long strength gain. This disadvantage not only led to the problems mentioned above but also delayed the opening of traffic, which, especially on roads of higher categories, caused traffic disruption and inconvenience to the movement of vehicles. The authors proposed a solution to this problem by developing an improved epoxy asphalt concrete composition by introducing fibre ash into the developed composition as a reinforcing and structuring additive that accelerates the pavement formation time and strengthens the asphalt matrix in epoxy asphalt concrete. Keywords: epoxy asphalt concrete, additive, fibre, fly ash, combustion products.

Low-flammability carbon fiber reinforced composites based on low-viscosity phosphorus-containing epoxy binders for transfer molding methods

This study is the first investigation into the possibility of low viscosity phosphorus-containing epoxy binders using triglycidyl phosphate for carbon fiber-reinforced polymers (CFRPs) production by resin transfer molding (RTM). Rheological studies and flammability evaluations were carried out to determine the optimum concentrations of triglycidyl phosphate in the epoxy binder. The introduction of triglycidyl phosphate into the epoxy composition was shown to produce self-extinguishing epoxy polymers. In addition, the curing kinetics of the phosphorus-containing epoxy binder was evaluated using differential scanning calorimetry (DSC) to optimize the curing process. The impregnation process of the product in the PAM-RTM software package was modeled to evaluate the possibility of obtaining large-size CFRP parts based on the developed binder by transfer molding methods. The physical-mechanical and fire-resistant tests of CFRPs showed significant improvement in flame-retardant properties in the modified samples, while maintaining high values of strength and elastic modulus. The study concluded that the introduced triglycidyl phosphate significantly affects the binder properties by reducing the viscosity, and increasing the flame retardancy, thus opening a promising direction for developing advanced composite materials.

Unlocking the potential of epoxy binders for efficient reclaimed asphalt pavement recycling: an experimental and molecular simulation study

ABSTRACT The efficient utilisation of reclaimed asphalt pavement (RAP) has emerged as a critical focal point within pavement recycling technology. High-performance epoxy binders show promise in achieving this objective. This study investigates the interaction mechanisms between epoxy systems and aged asphalt from three perspectives: macroscopic properties, microscopic phase structures, and molecular structure of the asphalt-epoxy system. Results reveal that the aged asphalt-epoxy system has increased elongation at break and decreased tensile strength. Microscopic assessments show that the phase structure of the aged asphalt-epoxy system is denser compared to neat asphalt-epoxy systems. The looser structure of neat asphalt-epoxy systems provides more space for epoxy system chemical reactions, leading to higher crosslinking compared to both pure epoxy and aged asphalt-epoxy systems. Additionally, the epoxy system exhibits better compatibility with aged asphalt than neat asphalt. At the molecular level, the epoxy system strongly adsorbs onto asphalt components, especially aged resin molecules. These findings contribute to the scientific application of epoxy binder in pavement recycling technology.

Исследование физико-химических превращений и структуры наномодифицированных эпоксидных связующих

The article presents the results of studies of epoxy binders and a comparative analysis of variant versions of basic formulations of synthetic resins and formulations modified with colloidal silicon dioxide and ultrafine zinc. The studies were carried out by instrumental methods using optical microscopy and differential scanning calorimetry, while the distribution of modifier nanoparticles in the volume of polymer matrices and their effect on the formation of the structure of cured binders were studied.

Determining the Rheological Parameters of Polymers Using Machine Learning Techniques

Introduction. The paper investigates the methodology for determining the rheological parameters of materials based on the nonlinear Maxwell-Gurevich rheological model using the stress relaxation curves. The review of the main directions of the metaheuristic approaches (local search, evolutionary algorithms) to solving the combinatorial optimization problems is presented. The metaheuristic algorithms for solving some important combinatorial optimization problems with the special emphasis on building decision trees are described. The comparative analysis of the algorithms for solving the regression problem in CatBoost Regressor is carried out. The aim of the work is to determine the rheological properties of polymers using machine learning techniques.Materials and Methods. The objects of the study are the generated data sets obtained on the basis of the theoretical stress relaxation curves. The source data tables for model training across all samples are presented, and the statistical analysis of the source data sets characteristics is carried out. The total number of numerical experiments across all samples amounted to 346020 variations. To develop the models, the CatBoost artificial intelligence techniques were used; the regularization techniques (Weight Decay, Decoupled Weight Decay Regulation, Augmentation) were used to increase the model accuracy; and Z–Score technique was used for data normalization.Results. As a result of the research, the intelligent models for determining the rheological parameters of polymers (initial relaxation viscosity, velocity modulus) have been developed based on the generated data sets on the example of the epoxy binder EDT-10. Based on the testing results of the models with the best parameters, the quality assessments were carried out: for the parameter 𝜂∗0 the range of values MAPE 0.46 — 2.72, MSE 0.15 — 1.09, RMSE 0.19 — 0.44, MAPE 0.46 — 1.27; for the parameter 𝑚∗ — MAPE 0.07 — 0.32, MSE 0.01 — 0.13, RMSE 0.10 — 0.41, MAPE 0.58 — 2.72. The resulting metric values are permissible. The training graphs demonstrate the stability of the process.Discussion and Conclusion. The developed intelligent models are scalable and cross-platform, have practical applied significance that ensures their implementation in a wide range of the scientific and engineering apps.

Increasing the Service Life of Marine Transport Using Heat-Resistant Polymer Nanocomposites.

This paper presents the technological aspects of increasing the thermal stability of polymers, with epoxy binder used to form the polymer materials. Polyethylene polyamine was used to crosslink the epoxy binder. To ensure the thermal stability of the polymer, nanodispersed condensed carbon with a dispersion of 10-16 nm was used. The research into nanocomposites under the influence of elevated temperatures was carried out using the "Thermoscan-2" derivatograph. Complex studies of thermophysical properties were carried out, according to the results of which the optimal content of nanofiller (0.050 pts.wt.) was determined. At the same time, this particular polymer was characterized by the following properties: temperature of the beginning of mass loss-T0 = 624.9 K; final temperature of mass loss-Tf = 718.7 K; relative mass loss-εm = 60.3%. Research into the activation energy of thermal destruction was performed to determine the resistance to the destruction of chemical bonds. It was proved that the maximum value of activation energy (170.1 kJ/mol) is characterized by nanocomposites with a content of nanodispersed condensed carbon of 0.050 pts.wt., which indicates the thermal stability of the polymer.

Strength Characteristics of Carbon Fiber Reinforced Plastic in Shear and Cyclic Extension-Compression after 7 Years of Climate Exposure

The results of studies of carbon fiber reinforced plastic (CFRP) for aviation purposes based on the Cycom 977-2 epoxy binder and Tenax® IMS carbon fibers after 7 years of exposure under a canopy and on an open atmospheric stand in the warm humid climate of Sochi are presented. The influence of climatic aging is determined by the change in strength parameters during interlaminar shear and cyclic tension – compression. After exposure under a canopy, the strength characteristics during interlaminar shear and cyclic tension–compression increase by 7–13 %. If the plate is under the direct influence of solar radiation, then the strength characteristics of the material are slightly reduced, but remain at the level of the original values. The kinetic concept of fracture was used to interpret the results. The thermal activation analysis showed that the characteristics of the inelasticity of the plate specimens, both in terms of the relaxation and hysteresis parts of energy absorption, correspond to their strength characteristics.

STUDY ON MECHANICAL PROPERTIES OF DEVELOPED ECO-FRIENDLY BRAKE PADS USING GRAY RELATIONAL ANALYSIS IN BOX BEHNKEN DESIGN OF EXPERIMENT

Over the years, asbestos has been a leading material for developing automobile brake pads. However, due to its hazardous nature to human health, many researchers have found that organic materials possess the potential for replacement. The organic materials used in this research were the hybrid of coconut fruit fibre CFF and oyster sea shell OSS. These materials were gathered from the river bank, dried, crushed, washed, ground, sieved, and moulded with different additives: CuO (abrasive), graphite (friction modifier or solid Lubricant), epoxy resin (binder), hardener (catalyst) by Box Behnken design BBD of L27 experiment. Therefore, an experimental test on mechanical properties was performed to check the developed brake pad's characterization. Then, grey relational analysis was used to analyze grey relational grade GRG to convert a multiple response process optimization problem into a single response optimization using maximization of maximum GRG. The optimum parameter values producing the highest value of grey relational grade were chosen as rank one, pertained to the factors setup for experiment number S3232 having moulding pressure of 11.25MPa, moulding temperature of 180oC, and heat treatment time of 180min. The optimized response values obtained from the experiment sample S3232 give the highest values on all the responses, i.e., density of 3.483g/cm3, hardness of 52.91BHN, compressive strength of 2.78MPa, ultimate tensile strength of 3.92MPa, impact energy of 17.87N, cold water absorption of 0.2863%, hot water absorption of 0.4785%, and oil absorption of 0.4402%. After that, the optimized brake pad sample (S3232) was applied to the automobile and was suitable for braking owing to its high mechanical properties.

The Influence of Epoxy Binder Electric Pulse Pretreatment on Mechanical Properties of Fiberglass

The Influence of Epoxy Binder Electric Pulse Pretreatment on Mechanical Properties of Fiberglass

Studies of the Physical Structure of Cured Epoxy Resin Composite Modified with Silicon-Containing Additives

Abstract The possibility of regulating the structure and reducing its defectiveness opens great possibilities for controlling the properties of epoxy composite materials. This article reports the results of investigation by X-ray scattering and nuclear magnetic resonance methods and the microstructural changes that occur when silicon-containing additives such as polydimethyl siloxane (PDMS-5) and pyrogenic silica (HDK) are introduced into epoxy resin ED-20. The mechanism of formation of the structure of epoxy binder ED-20 with L-20 curing agent in the presence of complex additives is found. The modifying additive (PDMS-5 + HDK) is located in the epoxy binder because of the chemical interaction of functional polar groups and the developed surface. The additives increase the mobility of the reaction mixture and also facilitate and regulate the spatial orientation of macromolecules during polymerization. This contributes to the formation of a more regular and less defective spatial structure. The epoxy binder is a heterogeneous two-component system, one of which corresponds to a pseudo-crystalline region in which the movement of molecules is suppressed, and the second is found at lower volume fractions and is amorphous. The only maximum in the wide-angle X-ray diffraction pattern of the binder without additives is attributable to the distribution of molecular chains in the para-crystalline lattice. The addition of the HDK additive leads to ordering of the supramolecular structure, in which linear clusters consisting of 5–7 spheres appear. The average size of the spheres is from 8 to 26 nm. The addition of additives in the samples leads to the formation of a more regular and less defective spatial structure because of the interaction of functional polar groups and the surface, which regulate the spatial orientation of macromolecules during polymerization.